Assert on valid order of which ids in ranges on SfxItemSet creation

This allows to make sure we actually use sorted which ranges,
and then it's safe to call SfxItemSet::MergeRange when needed.

Also this change relaxes the previous requirement that ranges
must be separated by at least one; this allows to have adjacent
ranges, like in

    RES_FRMATR_BEGIN, RES_FRMATR_END-1,
    RES_GRFATR_BEGIN, RES_GRFATR_END-1,

where RES_FRMATR_END is equal to RES_GRFATR_BEGIN. Allowing this
makes possible to (1) self-document the ranges, so it's clear
which ranges are included; and (2) be safe in case when these
constants would change, so that the one merged range would not
unexpectedly contain everything inserted between RES_FRMATR_END
and RES_GRFATR_BEGIN.

Change-Id: Iaad0f099b85059b3aa318a347aa7fbd3f6d455c7
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/116909
Tested-by: Jenkins
Reviewed-by: Mike Kaganski <mike.kaganski@collabora.com>
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/117106
Tested-by: Jenkins CollaboraOffice <jenkinscollaboraoffice@gmail.com>

25 files changed, 397 insertions, 579 deletions

diff --git a/chart2/source/controller/dialogs/dlg_NumberFormat.cxx b/chart2/source/controller/dialogs/dlg_NumberFormat.cxx
index d91b545cd027..3ba1bf68163f 100644
--- a/chart2/source/controller/dialogs/dlg_NumberFormat.cxx
+++ b/chart2/source/controller/dialogs/dlg_NumberFormat.cxx
@@ -44,15 +44,11 @@ NumberFormatDialog::NumberFormatDialog(weld::Window* pParent, SfxItemSet& rSet)
 
 SfxItemSet NumberFormatDialog::CreateEmptyItemSetForNumberFormatDialog( SfxItemPool& rItemPool )
 {
-    static const sal_uInt16 nWhichPairs[] =
-    {
+    return SfxItemSet( rItemPool, svl::Items<
         SID_ATTR_NUMBERFORMAT_VALUE, SID_ATTR_NUMBERFORMAT_INFO,
-        SID_ATTR_NUMBERFORMAT_NOLANGUAGE, SID_ATTR_NUMBERFORMAT_NOLANGUAGE,
         SID_ATTR_NUMBERFORMAT_ONE_AREA, SID_ATTR_NUMBERFORMAT_ONE_AREA,
-        SID_ATTR_NUMBERFORMAT_SOURCE, SID_ATTR_NUMBERFORMAT_SOURCE,
-        0
-    };
-    return SfxItemSet( rItemPool, nWhichPairs );
+        SID_ATTR_NUMBERFORMAT_NOLANGUAGE, SID_ATTR_NUMBERFORMAT_NOLANGUAGE,
+        SID_ATTR_NUMBERFORMAT_SOURCE, SID_ATTR_NUMBERFORMAT_SOURCE>{} );
 }
 
 } //namespace chart
diff --git a/chart2/source/controller/itemsetwrapper/SchWhichPairs.hxx b/chart2/source/controller/itemsetwrapper/SchWhichPairs.hxx
index ac08f2c99cf6..94d22f401d70 100644
--- a/chart2/source/controller/itemsetwrapper/SchWhichPairs.hxx
+++ b/chart2/source/controller/itemsetwrapper/SchWhichPairs.hxx
@@ -25,37 +25,36 @@
 
 #include <chartview/ChartSfxItemIds.hxx>
 
-#define CHARACTER_WHICHPAIRS \
-    EE_ITEMS_START, EE_ITEMS_END,  \
-    SID_CHAR_DLG_PREVIEW_STRING, SID_CHAR_DLG_PREVIEW_STRING
-
 const sal_uInt16 nTitleWhichPairs[] =
 {
     SCHATTR_TEXT_START, SCHATTR_TEXT_END,
     XATTR_LINE_FIRST, XATTR_LINE_LAST,              //  1000 -  1016  svx/xdef.hxx
     XATTR_FILL_FIRST, XATTR_FILL_LAST,              //  1018 -  1046  svx/xdef.hxx
     SDRATTR_SHADOW_FIRST, SDRATTR_SHADOW_LAST,      //  1067 -  1078  svx/svddef.hxx
-    CHARACTER_WHICHPAIRS,
+    EE_ITEMS_START, EE_ITEMS_END,                             // Characters
+    SID_CHAR_DLG_PREVIEW_STRING, SID_CHAR_DLG_PREVIEW_STRING, // Characters
     0
 };
 
 const sal_uInt16 nAxisWhichPairs[] =
 {
+    SCHATTR_TEXT_START, SCHATTR_TEXT_END,
+    SCHATTR_AXIS_START, SCHATTR_AXIS_END,
     XATTR_LINE_FIRST, XATTR_LINE_LAST,                          //  1000 -  1016  svx/xdef.hxx
-    CHARACTER_WHICHPAIRS,
+    EE_ITEMS_START, EE_ITEMS_END,                             // Characters
     SID_ATTR_NUMBERFORMAT_VALUE, SID_ATTR_NUMBERFORMAT_VALUE,   // 10585 - 10585  svx/svxids.hrc
     SID_ATTR_NUMBERFORMAT_SOURCE, SID_ATTR_NUMBERFORMAT_SOURCE, // 11432          svx/svxids.hrc
-    SCHATTR_AXIS_START, SCHATTR_AXIS_END,
-    SCHATTR_TEXT_START, SCHATTR_TEXT_END,
+    SID_CHAR_DLG_PREVIEW_STRING, SID_CHAR_DLG_PREVIEW_STRING, // Characters
     0
 };
 
 const sal_uInt16 nAllAxisWhichPairs[] =
 {
-    XATTR_LINE_FIRST, XATTR_LINE_LAST,
-    CHARACTER_WHICHPAIRS,
-    SCHATTR_AXIS_LABEL_START, SCHATTR_AXIS_LABEL_END,
     SCHATTR_TEXT_START, SCHATTR_TEXT_END,
+    SCHATTR_AXIS_LABEL_START, SCHATTR_AXIS_LABEL_END,
+    XATTR_LINE_FIRST, XATTR_LINE_LAST,
+    EE_ITEMS_START, EE_ITEMS_END,                             // Characters
+    SID_CHAR_DLG_PREVIEW_STRING, SID_CHAR_DLG_PREVIEW_STRING, // Characters
     0
 };
 
@@ -67,82 +66,86 @@ const sal_uInt16 nGridWhichPairs[] =
 
 const sal_uInt16 nLegendWhichPairs[] =
 {
+    SCHATTR_LEGEND_START, SCHATTR_LEGEND_END,       //     3 -     3  sch/schattr.hxx
     XATTR_LINE_FIRST, XATTR_LINE_LAST,              //  1000 -  1016  svx/xdef.hxx
     XATTR_FILL_FIRST, XATTR_FILL_LAST,              //  1018 -  1046  svx/xdef.hxx
     SDRATTR_SHADOW_FIRST, SDRATTR_SHADOW_LAST,      //  1067 -  1078  svx/svddef.hxx
-    CHARACTER_WHICHPAIRS,
-    SCHATTR_LEGEND_START, SCHATTR_LEGEND_END,       //     3 -     3  sch/schattr.hxx
+    EE_ITEMS_START, EE_ITEMS_END,                             // Characters
+    SID_CHAR_DLG_PREVIEW_STRING, SID_CHAR_DLG_PREVIEW_STRING, // Characters
     0
 };
 
 const sal_uInt16 nDataLabelWhichPairs[] =
 {
     SCHATTR_DATADESCR_START, SCHATTR_DATADESCR_END,
-    SID_ATTR_NUMBERFORMAT_VALUE, SID_ATTR_NUMBERFORMAT_INFO,    /* 10585 - 10585  svx/svxids.hrc */
-    SID_ATTR_NUMBERFORMAT_SOURCE, SID_ATTR_NUMBERFORMAT_SOURCE, /* 11432          svx/svxids.hrc */
     SCHATTR_TEXT_DEGREES,SCHATTR_TEXT_DEGREES,
     EE_PARA_WRITINGDIR,EE_PARA_WRITINGDIR,
+    SID_ATTR_NUMBERFORMAT_VALUE, SID_ATTR_NUMBERFORMAT_INFO,    /* 10585 - 10585  svx/svxids.hrc */
+    SID_ATTR_NUMBERFORMAT_SOURCE, SID_ATTR_NUMBERFORMAT_SOURCE, /* 11432          svx/svxids.hrc */
     0
 };
 
-#define CHART_POINT_WHICHPAIRS  \
-    XATTR_LINE_FIRST, XATTR_LINE_LAST,              /*  1000 -  1016  svx/xdef.hxx   */ \
-    XATTR_FILL_FIRST, XATTR_FILL_LAST,              /*  1018 -  1046  svx/xdef.hxx   */ \
-    EE_ITEMS_START, EE_ITEMS_END,                   /*  3994 -  4037  editeng/eeitem.hxx */ \
-    SID_CHAR_DLG_PREVIEW_STRING, SID_CHAR_DLG_PREVIEW_STRING, \
-    SCHATTR_DATADESCR_START, SCHATTR_DATADESCR_END, /*     1 -     2  sch/schattr.hxx*/ \
-    SID_ATTR_NUMBERFORMAT_VALUE, SID_ATTR_NUMBERFORMAT_INFO,    /* 10585 - 10585  svx/svxids.hrc */ \
-    SID_ATTR_NUMBERFORMAT_SOURCE, SID_ATTR_NUMBERFORMAT_SOURCE, /* 11432          svx/svxids.hrc */ \
-    SCHATTR_TEXT_DEGREES, SCHATTR_TEXT_DEGREES, \
-    SCHATTR_STYLE_START,SCHATTR_STYLE_END,          /*    59 -    68  sch/schattr.hxx*/ \
-    SCHATTR_SYMBOL_BRUSH,SCHATTR_SYMBOL_BRUSH,      /*    94          sch/schattr.hxx*/ \
-    SCHATTR_SYMBOL_SIZE,SCHATTR_SYMBOL_SIZE,        /*    97          sch/schattr.hxx*/ \
-    SDRATTR_3D_FIRST, SDRATTR_3D_LAST,              /*  1244 -  1334  svx/svddef.hxx */ \
-    SCHATTR_HIDE_DATA_POINT_LEGEND_ENTRY, SCHATTR_HIDE_DATA_POINT_LEGEND_ENTRY
-
 const sal_uInt16 nDataPointWhichPairs[] =
 {
-    CHART_POINT_WHICHPAIRS,
+    SCHATTR_DATADESCR_START, SCHATTR_DATADESCR_END, /*     1 -     2  sch/schattr.hxx*/
+    SCHATTR_TEXT_DEGREES, SCHATTR_TEXT_DEGREES,
+    SCHATTR_STYLE_START,SCHATTR_STYLE_END,          /*    59 -    68  sch/schattr.hxx*/
+    SCHATTR_SYMBOL_BRUSH,SCHATTR_SYMBOL_BRUSH,      /*    94          sch/schattr.hxx*/
+    SCHATTR_SYMBOL_SIZE,SCHATTR_SYMBOL_SIZE,        /*    97          sch/schattr.hxx*/
+    SCHATTR_HIDE_DATA_POINT_LEGEND_ENTRY, SCHATTR_HIDE_DATA_POINT_LEGEND_ENTRY,
+    XATTR_LINE_FIRST, XATTR_LINE_LAST,              /*  1000 -  1016  svx/xdef.hxx   */
+    XATTR_FILL_FIRST, XATTR_FILL_LAST,              /*  1018 -  1046  svx/xdef.hxx   */
+    SDRATTR_3D_FIRST, SDRATTR_3D_LAST,              /*  1244 -  1334  svx/svddef.hxx */
+    EE_ITEMS_START, EE_ITEMS_END,                   /*  3994 -  4037  editeng/eeitem.hxx */
+    SID_ATTR_NUMBERFORMAT_VALUE, SID_ATTR_NUMBERFORMAT_INFO,    /* 10585 - 10585  svx/svxids.hrc */
+    SID_ATTR_NUMBERFORMAT_SOURCE, SID_ATTR_NUMBERFORMAT_SOURCE, /* 11432          svx/svxids.hrc */
+    SID_CHAR_DLG_PREVIEW_STRING, SID_CHAR_DLG_PREVIEW_STRING,
     0
 };
 
 const sal_uInt16 nTextLabelWhichPairs[] =
 {
-    XATTR_LINESTYLE, XATTR_LINECOLOR,
-    XATTR_LINETRANSPARENCE, XATTR_LINETRANSPARENCE,
-    EE_ITEMS_START, EE_ITEMS_END,
-    SID_CHAR_DLG_PREVIEW_STRING, SID_CHAR_DLG_PREVIEW_STRING,
     SCHATTR_DATADESCR_START, SCHATTR_DATADESCR_END,
-    SID_ATTR_NUMBERFORMAT_VALUE, SID_ATTR_NUMBERFORMAT_INFO,
-    SID_ATTR_NUMBERFORMAT_SOURCE, SID_ATTR_NUMBERFORMAT_SOURCE,
     SCHATTR_TEXT_DEGREES, SCHATTR_TEXT_DEGREES,
     SCHATTR_STYLE_SYMBOL, SCHATTR_STYLE_SYMBOL,
     SCHATTR_SYMBOL_BRUSH, SCHATTR_SYMBOL_BRUSH,
     SCHATTR_SYMBOL_SIZE, SCHATTR_SYMBOL_SIZE,
+    XATTR_LINESTYLE, XATTR_LINECOLOR,
+    XATTR_LINETRANSPARENCE, XATTR_LINETRANSPARENCE,
+    EE_ITEMS_START, EE_ITEMS_END,
+    SID_ATTR_NUMBERFORMAT_VALUE, SID_ATTR_NUMBERFORMAT_INFO,
+    SID_ATTR_NUMBERFORMAT_SOURCE, SID_ATTR_NUMBERFORMAT_SOURCE,
+    SID_CHAR_DLG_PREVIEW_STRING, SID_CHAR_DLG_PREVIEW_STRING,
     0
 };
 
-#define CHART_SERIES_OPTIONS_WHICHPAIRS \
-    SCHATTR_AXIS,SCHATTR_AXIS,                      /*    69          sch/schattr.hxx*/ \
-    SCHATTR_BAR_OVERLAP,SCHATTR_BAR_CONNECT,         /*    98 - 100 (incl. SCHATTR_GAPWIDTH) */  \
-    SCHATTR_GROUP_BARS_PER_AXIS,SCHATTR_AXIS_FOR_ALL_SERIES, \
-    SCHATTR_STARTING_ANGLE,SCHATTR_STARTING_ANGLE, \
-    SCHATTR_CLOCKWISE,SCHATTR_CLOCKWISE, \
-    SCHATTR_MISSING_VALUE_TREATMENT,SCHATTR_MISSING_VALUE_TREATMENT, \
-    SCHATTR_AVAILABLE_MISSING_VALUE_TREATMENTS,SCHATTR_AVAILABLE_MISSING_VALUE_TREATMENTS, \
-    SCHATTR_INCLUDE_HIDDEN_CELLS,SCHATTR_INCLUDE_HIDDEN_CELLS, \
-    SCHATTR_HIDE_LEGEND_ENTRY,SCHATTR_HIDE_LEGEND_ENTRY
-
 const sal_uInt16 nSeriesOptionsWhichPairs[] =
 {
-    CHART_SERIES_OPTIONS_WHICHPAIRS,
+    SCHATTR_AXIS,SCHATTR_AXIS,                      /*    69          sch/schattr.hxx*/
+    SCHATTR_BAR_OVERLAP,SCHATTR_BAR_CONNECT,         /*    98 - 100 (incl. SCHATTR_GAPWIDTH) */
+    SCHATTR_GROUP_BARS_PER_AXIS,SCHATTR_AXIS_FOR_ALL_SERIES,
     0
 };
 
+// nDataPointWhichPairs + nSeriesOptionsWhichPairs
 const sal_uInt16 nRowWhichPairs[] =
 {
-    CHART_POINT_WHICHPAIRS,
-    CHART_SERIES_OPTIONS_WHICHPAIRS,
+    SCHATTR_DATADESCR_START, SCHATTR_DATADESCR_END, /*     1 -     2  sch/schattr.hxx*/
+    SCHATTR_TEXT_DEGREES, SCHATTR_TEXT_DEGREES,
+    SCHATTR_STYLE_START,SCHATTR_STYLE_END,          /*    59 -    68  sch/schattr.hxx*/
+    SCHATTR_AXIS,SCHATTR_AXIS,                      /*    69          sch/schattr.hxx*/
+    SCHATTR_SYMBOL_BRUSH,SCHATTR_SYMBOL_BRUSH,      /*    94          sch/schattr.hxx*/
+    SCHATTR_SYMBOL_SIZE,SCHATTR_SYMBOL_SIZE,        /*    97          sch/schattr.hxx*/
+    SCHATTR_HIDE_DATA_POINT_LEGEND_ENTRY, SCHATTR_HIDE_DATA_POINT_LEGEND_ENTRY,
+    SCHATTR_BAR_OVERLAP,SCHATTR_BAR_CONNECT,         /*    98 - 100 (incl. SCHATTR_GAPWIDTH) */
+    SCHATTR_GROUP_BARS_PER_AXIS,SCHATTR_AXIS_FOR_ALL_SERIES,
+    XATTR_LINE_FIRST, XATTR_LINE_LAST,              /*  1000 -  1016  svx/xdef.hxx   */
+    XATTR_FILL_FIRST, XATTR_FILL_LAST,              /*  1018 -  1046  svx/xdef.hxx   */
+    SDRATTR_3D_FIRST, SDRATTR_3D_LAST,              /*  1244 -  1334  svx/svddef.hxx */
+    EE_ITEMS_START, EE_ITEMS_END,                   /*  3994 -  4037  editeng/eeitem.hxx */
+    SID_ATTR_NUMBERFORMAT_VALUE, SID_ATTR_NUMBERFORMAT_INFO,    /* 10585 - 10585  svx/svxids.hrc */
+    SID_ATTR_NUMBERFORMAT_SOURCE, SID_ATTR_NUMBERFORMAT_SOURCE, /* 11432          svx/svxids.hrc */
+    SID_CHAR_DLG_PREVIEW_STRING, SID_CHAR_DLG_PREVIEW_STRING,
     0
 };
 
@@ -164,7 +167,8 @@ const sal_uInt16 nErrorBarWhichPairs[]=
 
 const sal_uInt16 nCharacterPropertyWhichPairs[] =
 {
-    CHARACTER_WHICHPAIRS,
+    EE_ITEMS_START, EE_ITEMS_END,                             // Characters
+    SID_CHAR_DLG_PREVIEW_STRING, SID_CHAR_DLG_PREVIEW_STRING, // Characters
     0
 };
 
@@ -194,8 +198,9 @@ const sal_uInt16 nRegEquationWhichPairs[] =
     XATTR_LINE_FIRST, XATTR_LINE_LAST,              //  1000 -  1016  svx/xdef.hxx
     XATTR_FILL_FIRST, XATTR_FILL_LAST,              //  1018 -  1046  svx/xdef.hxx
     SDRATTR_SHADOW_FIRST, SDRATTR_SHADOW_LAST,      //  1067 -  1078  svx/svddef.hxx
-    CHARACTER_WHICHPAIRS,
+    EE_ITEMS_START, EE_ITEMS_END,                             // Characters
     SID_ATTR_NUMBERFORMAT_VALUE, SID_ATTR_NUMBERFORMAT_VALUE,   // 10585 - 10585  svx/svxids.hrc
+    SID_CHAR_DLG_PREVIEW_STRING, SID_CHAR_DLG_PREVIEW_STRING, // Characters
     0
 };
 
diff --git a/include/svl/itemset.hxx b/include/svl/itemset.hxx
index 94ee142a2e77..80d8ad5b4237 100644
--- a/include/svl/itemset.hxx
+++ b/include/svl/itemset.hxx
@@ -21,11 +21,13 @@
 
 #include <sal/config.h>
 
+#include <array>
 #include <cassert>
 #include <cstddef>
 #include <initializer_list>
 #include <type_traits>
 #include <memory>
+#include <utility>
 
 #include <svl/svldllapi.h>
 #include <svl/poolitem.hxx>
@@ -41,7 +43,7 @@ constexpr bool validRange(sal_uInt16 wid1, sal_uInt16 wid2)
 { return wid1 != 0 && wid1 <= wid2; }
 
 constexpr bool validGap(sal_uInt16 wid1, sal_uInt16 wid2)
-{ return wid2 > wid1 && wid2 - wid1 > 1; }
+{ return wid2 > wid1; }
 
 template<sal_uInt16 WID1, sal_uInt16 WID2> constexpr bool validRanges()
 { return validRange(WID1, WID2); }
@@ -52,6 +54,19 @@ constexpr bool validRanges() {
         && validRanges<WID3, WIDs...>();
 }
 
+inline constexpr bool validRanges(const sal_uInt16* pRanges)
+{
+    for (auto p = pRanges; p && *p; p += 2)
+    {
+        if (!validRange(p[0], p[1]))
+            return false;
+        // ranges must be sorted
+        if (p[2] != 0 && !validGap(p[1], p[2]))
+            return false;
+    }
+    return true;
+}
+
 // The calculations in rangeSize and rangesSize cannot overflow, assuming
 // std::size_t is no smaller than sal_uInt16:
 
@@ -71,6 +86,24 @@ constexpr std::size_t rangesSize()
 
 template<sal_uInt16... WIDs> struct Items {};
 
+// This allows creating compile-time which id arrays using syntax like
+//
+//     constexpr auto aWids = svl::ItemsArray({ { widFrom1, widTo2 }, { widFrom2, widTo2 }, ... });
+//
+// so that e.g. clang-format would not try to rearrange the initializer sequence to break pairs.
+// Additionally, the array validity is checked in debug builds.
+template <size_t N> constexpr auto ItemsArray(const std::pair<sal_uInt16, sal_uInt16> (&wids)[N])
+{
+    std::array<sal_uInt16, N * 2 + 1> aArray{};
+    sal_uInt16* p = aArray.data();
+    for (const auto& [wid1, wid2] : wids)
+    {
+        *p++ = wid1;
+        *p++ = wid2;
+    }
+    assert(svl::detail::validRanges(aArray.data()));
+    return aArray;
+}
 }
 
 class SAL_WARN_UNUSED SVL_DLLPUBLIC SfxItemSet
@@ -88,7 +121,7 @@ friend class SfxItemPoolCache;
 friend class SfxAllItemSet;
 
 private:
-    SVL_DLLPRIVATE void                     InitRanges_Impl(const sal_uInt16 *nWhichPairTable);
+    SVL_DLLPRIVATE sal_uInt16 InitRanges_Impl(const sal_uInt16 *nWhichPairTable);
 
     SfxItemSet(
         SfxItemPool & pool, std::initializer_list<sal_uInt16> wids,
@@ -248,8 +281,6 @@ class SVL_DLLPUBLIC SfxAllItemSet: public SfxItemSet
 //  Handles all Ranges. Ranges are automatically modified by putting items.
 
 {
-    sal_uInt16                      nFree;
-
 public:
                                 SfxAllItemSet( SfxItemPool &rPool );
                                 SfxAllItemSet( const SfxItemSet & );
diff --git a/sc/source/ui/dbgui/validate.cxx b/sc/source/ui/dbgui/validate.cxx
index 0ee9b69ab83a..ddd09086f144 100644
--- a/sc/source/ui/dbgui/validate.cxx
+++ b/sc/source/ui/dbgui/validate.cxx
@@ -80,8 +80,8 @@ namespace ValidListType = css::sheet::TableValidationVisibility;
 
 const sal_uInt16 ScTPValidationValue::pValueRanges[] =
 {
-    FID_VALID_MODE, FID_VALID_ERRTEXT,
     FID_VALID_LISTTYPE, FID_VALID_LISTTYPE,
+    FID_VALID_MODE, FID_VALID_ERRTEXT,
     0
 };
 
diff --git a/sd/source/ui/func/fupage.cxx b/sd/source/ui/func/fupage.cxx
index 6d44b70d5a9d..6adf302d5607 100644
--- a/sd/source/ui/func/fupage.cxx
+++ b/sd/source/ui/func/fupage.cxx
@@ -200,15 +200,17 @@ const SfxItemSet* FuPage::ExecuteDialog(weld::Window* pParent, const SfxRequest&
     if (!mpDrawViewShell)
         return nullptr;
 
-    SfxItemSet aNewAttr(mpDoc->GetPool(),
-                        {{mpDoc->GetPool().GetWhich(SID_ATTR_LRSPACE),
-                        mpDoc->GetPool().GetWhich(SID_ATTR_ULSPACE)},
-                        {SID_ATTR_PAGE, SID_ATTR_PAGE_SHARED},
-                        {SID_ATTR_BORDER_OUTER, SID_ATTR_BORDER_OUTER},
-                        {SID_ATTR_BORDER_SHADOW, SID_ATTR_BORDER_SHADOW},
-                        {XATTR_FILL_FIRST, XATTR_FILL_LAST},
-                        {SID_ATTR_PAGE_COLOR,SID_ATTR_PAGE_FILLSTYLE},
-                        {EE_PARA_WRITINGDIR, EE_PARA_WRITINGDIR}});
+    SfxItemSet aNewAttr(mpDoc->GetPool(), {
+                                              { XATTR_FILL_FIRST, XATTR_FILL_LAST },
+                                              { EE_PARA_WRITINGDIR, EE_PARA_WRITINGDIR },
+                                              { SID_ATTR_BORDER_OUTER, SID_ATTR_BORDER_OUTER },
+                                              { SID_ATTR_BORDER_SHADOW, SID_ATTR_BORDER_SHADOW },
+                                              { SID_ATTR_PAGE, SID_ATTR_PAGE_SHARED },
+                                              { SID_ATTR_PAGE_COLOR, SID_ATTR_PAGE_FILLSTYLE },
+                                          });
+    // Keep it sorted
+    aNewAttr.MergeRange(mpDoc->GetPool().GetWhich(SID_ATTR_LRSPACE),
+                        mpDoc->GetPool().GetWhich(SID_ATTR_ULSPACE));
 
     // Retrieve additional data for dialog
 
diff --git a/sfx2/source/control/bindings.cxx b/sfx2/source/control/bindings.cxx
index d648fdf87537..1792e330f5c4 100644
--- a/sfx2/source/control/bindings.cxx
+++ b/sfx2/source/control/bindings.cxx
@@ -1162,21 +1162,18 @@ std::unique_ptr<SfxItemSet> SfxBindings::CreateSet_Impl
     }
 
     // Create a Set from the ranges
-    std::unique_ptr<sal_uInt16[]> pRanges(new sal_uInt16[rFound.size() * 2 + 1]);
-    int j = 0;
     size_t i = 0;
+    auto pSet(std::make_unique<SfxItemSet>(rPool, nullptr));
     while ( i < rFound.size() )
     {
-        pRanges[j++] = rFound[i].nWhichId;
+        const sal_uInt16 nWhich1 = rFound[i].nWhichId;
             // consecutive numbers
         for ( ; i < rFound.size()-1; ++i )
             if ( rFound[i].nWhichId+1 != rFound[i+1].nWhichId )
                 break;
-        pRanges[j++] = rFound[i++].nWhichId;
+        const sal_uInt16 nWhich2 = rFound[i++].nWhichId;
+        pSet->MergeRange(nWhich1, nWhich2);
     }
-    pRanges[j] = 0; // terminating NULL
-    std::unique_ptr<SfxItemSet> pSet(new SfxItemSet(rPool, pRanges.get()));
-    pRanges.reset();
     return pSet;
 }
 
diff --git a/sfx2/source/dialog/tabdlg.cxx b/sfx2/source/dialog/tabdlg.cxx
index 484b431a690e..c18139dbc347 100644
--- a/sfx2/source/dialog/tabdlg.cxx
+++ b/sfx2/source/dialog/tabdlg.cxx
@@ -687,7 +687,7 @@ const sal_uInt16* SfxTabDialogController::GetInputRanges(const SfxItemPool& rPoo
 
     if ( m_pRanges )
         return m_pRanges.get();
-    std::vector<sal_uInt16> aUS;
+    SfxItemSet aUS(const_cast<SfxItemPool&>(rPool));
 
     for (auto const& elem : m_pImpl->aData)
     {
@@ -695,30 +695,24 @@ const sal_uInt16* SfxTabDialogController::GetInputRanges(const SfxItemPool& rPoo
         if ( elem->fnGetRanges )
         {
             const sal_uInt16* pTmpRanges = (elem->fnGetRanges)();
-            const sal_uInt16* pIter = pTmpRanges;
 
-            sal_uInt16 nLen;
-            for( nLen = 0; *pIter; ++nLen, ++pIter )
-                ;
-            aUS.insert( aUS.end(), pTmpRanges, pTmpRanges + nLen );
+            for (const sal_uInt16* pIter = pTmpRanges; *pIter;)
+            {
+                sal_uInt16 nWidFrom = rPool.GetWhich(*pIter++);
+                assert(*pIter);
+                sal_uInt16 nWidTo = rPool.GetWhich(*pIter++);
+                aUS.MergeRange(nWidFrom, nWidTo); // Keep it valid
+            }
         }
     }
 
-    //! Remove duplicated Ids?
-    {
-        for (auto & elem : aUS)
-            elem = rPool.GetWhich(elem);
-    }
-
-    // sort
-    if ( aUS.size() > 1 )
-    {
-        std::sort( aUS.begin(), aUS.end() );
-    }
+    int nSize = 0;
+    for (const sal_uInt16* pIter = aUS.GetRanges(); pIter && *pIter; pIter++)
+        ++nSize;
 
-    m_pRanges.reset(new sal_uInt16[aUS.size() + 1]);
-    std::copy( aUS.begin(), aUS.end(), m_pRanges.get() );
-    m_pRanges[aUS.size()] = 0;
+    m_pRanges.reset(new sal_uInt16[nSize + 1]);
+    std::copy(aUS.GetRanges(), aUS.GetRanges() + nSize, m_pRanges.get());
+    m_pRanges[nSize] = 0;
     return m_pRanges.get();
 }
 
diff --git a/starmath/source/unomodel.cxx b/starmath/source/unomodel.cxx
index 623fad785844..7628768ae50b 100644
--- a/starmath/source/unomodel.cxx
+++ b/starmath/source/unomodel.cxx
@@ -607,19 +607,15 @@ void SmModel::_setPropertyValues(const PropertyMapEntry** ppEntries, const Any*
                 sal_uInt32 nSize = aSequence.getLength();
                 SvMemoryStream aStream ( aSequence.getArray(), nSize, StreamMode::READ );
                 aStream.Seek ( STREAM_SEEK_TO_BEGIN );
-                static sal_uInt16 const nRange[] =
-                {
-                    SID_PRINTSIZE,       SID_PRINTSIZE,
-                    SID_PRINTZOOM,       SID_PRINTZOOM,
+                auto pItemSet = std::make_unique<SfxItemSet>( SmDocShell::GetPool(), svl::Items<
                     SID_PRINTTITLE,      SID_PRINTTITLE,
                     SID_PRINTTEXT,       SID_PRINTTEXT,
                     SID_PRINTFRAME,      SID_PRINTFRAME,
+                    SID_PRINTSIZE,       SID_PRINTSIZE,
+                    SID_PRINTZOOM,       SID_PRINTZOOM,
                     SID_NO_RIGHT_SPACES, SID_NO_RIGHT_SPACES,
                     SID_SAVE_ONLY_USED_SYMBOLS, SID_SAVE_ONLY_USED_SYMBOLS,
-                    SID_AUTO_CLOSE_BRACKETS,    SID_AUTO_CLOSE_BRACKETS,
-                    0
-                };
-                auto pItemSet = std::make_unique<SfxItemSet>( SmDocShell::GetPool(), nRange );
+                    SID_AUTO_CLOSE_BRACKETS,    SID_AUTO_CLOSE_BRACKETS>{} );
                 SmModule *pp = SM_MOD();
                 pp->GetConfig()->ConfigToItemSet(*pItemSet);
                 VclPtr<SfxPrinter> pPrinter = SfxPrinter::Create ( aStream, std::move(pItemSet) );
diff --git a/svl/source/inc/items_helper.hxx b/svl/source/inc/items_helper.hxx
new file mode 100644
index 000000000000..75582d9f8741
--- /dev/null
+++ b/svl/source/inc/items_helper.hxx
@@ -0,0 +1,126 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4; fill-column: 100 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ * This file incorporates work covered by the following license notice:
+ *
+ *   Licensed to the Apache Software Foundation (ASF) under one or more
+ *   contributor license agreements. See the NOTICE file distributed
+ *   with this work for additional information regarding copyright
+ *   ownership. The ASF licenses this file to you under the Apache
+ *   License, Version 2.0 (the "License"); you may not use this file
+ *   except in compliance with the License. You may obtain a copy of
+ *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
+ */
+
+#pragma once
+
+#include <sal/config.h>
+
+#include <sal/types.h>
+#include <svl/itemset.hxx>
+
+#include <memory>
+#include <utility>
+#include <vector>
+
+namespace svl::detail
+{
+/**
+ * Determines the number of sal_uInt16s in a 0-terminated array of pairs of
+ * sal_uInt16s, each representing a range of sal_uInt16s, and total capacity of the ranges.
+ * The terminating 0 is included in the count.
+ */
+inline std::pair<sal_uInt16, sal_uInt16> CountRanges(const sal_uInt16* pRanges)
+{
+    sal_uInt16 nCount = 0;
+    sal_uInt16 nCapacity = 0;
+    if (pRanges)
+    {
+        nCount = 1;
+        while (*pRanges)
+        {
+            nCount += 2;
+            nCapacity += rangeSize(pRanges[0], pRanges[1]);
+            pRanges += 2;
+        }
+    }
+    return { nCount, nCapacity };
+}
+
+// Adds a range to which ranges, keeping the ranges in valid state (sorted, non-overlapping)
+inline std::unique_ptr<sal_uInt16[]> MergeRange(const sal_uInt16* pWhichRanges, sal_uInt16 nFrom,
+                                                sal_uInt16 nTo)
+{
+    assert(validRange(nFrom, nTo));
+
+    if (!pWhichRanges)
+    {
+        auto pNewRanges = std::make_unique<sal_uInt16[]>(3);
+        pNewRanges[0] = nFrom;
+        pNewRanges[1] = nTo;
+        pNewRanges[2] = 0;
+        return pNewRanges;
+    }
+
+    assert(validRanges(pWhichRanges));
+
+    // create vector of ranges (sal_uInt16 pairs of lower and upper bound)
+    const size_t nOldCount = CountRanges(pWhichRanges).first;
+    std::vector<std::pair<sal_uInt16, sal_uInt16>> aRangesTable;
+    aRangesTable.reserve(nOldCount / 2 + 1);
+    bool bAdded = false;
+    for (size_t i = 0; i + 1 < nOldCount; i += 2)
+    {
+        if (!bAdded && pWhichRanges[i] >= nFrom)
+        { // insert new range, keep ranges sorted
+            aRangesTable.emplace_back(std::pair<sal_uInt16, sal_uInt16>(nFrom, nTo));
+            bAdded = true;
+        }
+        // insert current range
+        aRangesTable.emplace_back(
+            std::pair<sal_uInt16, sal_uInt16>(pWhichRanges[i], pWhichRanges[i + 1]));
+    }
+    if (!bAdded)
+        aRangesTable.emplace_back(std::pair<sal_uInt16, sal_uInt16>(nFrom, nTo));
+
+    // true if ranges overlap or adjoin, false if ranges are separate
+    auto needMerge
+        = [](std::pair<sal_uInt16, sal_uInt16> lhs, std::pair<sal_uInt16, sal_uInt16> rhs) {
+              return (lhs.first - 1) <= rhs.second && (rhs.first - 1) <= lhs.second;
+          };
+
+    auto it = aRangesTable.begin();
+    // we got at least one range
+    for (;;)
+    {
+        auto itNext = std::next(it);
+        if (itNext == aRangesTable.end())
+            break;
+        // check neighbouring ranges, find first range which overlaps or adjoins a previous range
+        if (needMerge(*it, *itNext))
+        {
+            // lower bounds are sorted, implies: it->first = min(it[0].first, it[1].first)
+            it->second = std::max(it->second, itNext->second);
+            aRangesTable.erase(itNext);
+        }
+        else
+            ++it;
+    }
+
+    // construct range array
+    const size_t nNewSize = 2 * aRangesTable.size() + 1;
+    auto pNewRanges = std::make_unique<sal_uInt16[]>(nNewSize);
+    for (size_t i = 0; i < (nNewSize - 1); i += 2)
+        std::tie(pNewRanges[i], pNewRanges[i + 1]) = aRangesTable[i / 2];
+
+    pNewRanges[nNewSize - 1] = 0;
+    return pNewRanges;
+}
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab cinoptions=b1,g0,N-s cinkeys+=0=break: */
diff --git a/svl/source/items/itempool.cxx b/svl/source/items/itempool.cxx
index 6deec84947c0..c6fcd488265d 100644
--- a/svl/source/items/itempool.cxx
+++ b/svl/source/items/itempool.cxx
@@ -28,6 +28,8 @@
 #include <svl/SfxBroadcaster.hxx>
 #include <svl/hint.hxx>
 #include <svl/itemset.hxx>
+
+#include <items_helper.hxx>
 #include <poolio.hxx>
 
 #include <algorithm>
@@ -795,20 +797,12 @@ void SfxItemPool::FillItemIdRanges_Impl( std::unique_ptr<sal_uInt16[]>& pWhichRa
 {
     DBG_ASSERT( !pImpl->mpPoolRanges, "GetFrozenRanges() would be faster!" );
 
-    const SfxItemPool *pPool;
-    sal_uInt16 nLevel = 0;
-    for( pPool = this; pPool; pPool = pPool->pImpl->mpSecondary )
-        ++nLevel;
-
-    pWhichRanges.reset(new sal_uInt16[ 2*nLevel + 1 ]);
+    pWhichRanges.reset();
 
-    nLevel = 0;
-    for( pPool = this; pPool; pPool = pPool->pImpl->mpSecondary )
-    {
-        pWhichRanges[nLevel++] = pPool->pImpl->mnStart;
-        pWhichRanges[nLevel++] = pPool->pImpl->mnEnd;
-        pWhichRanges[nLevel] = 0;
-    }
+    // Merge all ranges, keeping them sorted
+    for (const SfxItemPool* pPool = this; pPool; pPool = pPool->pImpl->mpSecondary)
+        pWhichRanges = svl::detail::MergeRange(pWhichRanges.get(), pPool->pImpl->mnStart,
+                                               pPool->pImpl->mnEnd);
 }
 
 const sal_uInt16* SfxItemPool::GetFrozenIdRanges() const
diff --git a/svl/source/items/itemset.cxx b/svl/source/items/itemset.cxx
index 8d7b1e463911..d4e808463f71 100644
--- a/svl/source/items/itemset.cxx
+++ b/svl/source/items/itemset.cxx
@@ -32,47 +32,7 @@
 #include <svl/itemiter.hxx>
 #include <svl/whiter.hxx>
 
-const sal_uInt16 nInitCount = 10; // Single USHORTs => 5 pairs without '0'
-
-namespace
-{
-
-/**
- * Determines the number of sal_uInt16s in a 0-terminated array of pairs of
- * sal_uInt16s.
- * The terminating 0 is not included in the count.
- */
-sal_uInt16 Count_Impl( const sal_uInt16 *pRanges )
-{
-    sal_uInt16 nCount = 0;
-    while ( *pRanges )
-    {
-        nCount += 2;
-        pRanges += 2;
-    }
-    return nCount;
-}
-
-/**
- * Determines the total number of sal_uInt16s described in a 0-terminated
- * array of pairs of sal_uInt16s, each representing a range of sal_uInt16s.
- */
-sal_uInt16 Capacity_Impl( const sal_uInt16 *pRanges )
-{
-    sal_uInt16 nCount = 0;
-
-    if ( pRanges )
-    {
-        while ( *pRanges )
-        {
-            nCount += pRanges[1] - pRanges[0] + 1;
-            pRanges += 2;
-        }
-    }
-    return nCount;
-}
-
-}
+#include <items_helper.hxx>
 
 /**
  * Ctor for a SfxItemSet with exactly the Which Ranges, which are known to
@@ -94,26 +54,20 @@ SfxItemSet::SfxItemSet(SfxItemPool& rPool)
         m_pPool->FillItemIdRanges_Impl(tmp);
         m_pWhichRanges = tmp.release();
     }
+    assert(svl::detail::validRanges(m_pWhichRanges));
 
     const sal_uInt16 nSize = TotalCount();
     m_pItems.reset(new const SfxPoolItem*[nSize]{});
 }
 
-void SfxItemSet::InitRanges_Impl(const sal_uInt16 *pWhichPairTable)
+sal_uInt16 SfxItemSet::InitRanges_Impl(const sal_uInt16 *pWhichPairTable)
 {
-    sal_uInt16 nCnt = 0;
-    const sal_uInt16* pPtr = pWhichPairTable;
-    while( *pPtr )
-    {
-        nCnt += ( *(pPtr+1) - *pPtr ) + 1;
-        pPtr += 2;
-    }
-
-    m_pItems.reset( new const SfxPoolItem*[nCnt]{} );
-
-    std::ptrdiff_t cnt = pPtr - pWhichPairTable +1;
-    m_pWhichRanges = new sal_uInt16[ cnt ];
-    memcpy( m_pWhichRanges, pWhichPairTable, sizeof( sal_uInt16 ) * cnt );
+    const auto& [nCnt, nCap] = svl::detail::CountRanges(pWhichPairTable);
+    m_pItems.reset(new const SfxPoolItem* [nCap] {});
+    m_pWhichRanges = new sal_uInt16[nCnt];
+    memcpy(m_pWhichRanges, pWhichPairTable, sizeof(sal_uInt16) * nCnt);
+    assert(svl::detail::validRanges(m_pWhichRanges));
+    return nCap;
 }
 
 SfxItemSet::SfxItemSet(
@@ -132,6 +86,7 @@ SfxItemSet::SfxItemSet(
     assert(wids.size() % 2 == 0);
     std::copy(wids.begin(), wids.end(), m_pWhichRanges);
     m_pWhichRanges[wids.size()] = 0;
+    assert(svl::detail::validRanges(m_pWhichRanges));
 }
 
 SfxItemSet::SfxItemSet(
@@ -143,22 +98,15 @@ SfxItemSet::SfxItemSet(
     assert(wids.size() != 0);
     std::size_t i = 0;
     std::size_t size = 0;
-#if !defined NDEBUG
-    //TODO: sal_uInt16 prev = 0;
-#endif
     for (auto const & p: wids) {
-        assert(svl::detail::validRange(p.wid1, p.wid2));
-        //TODO: assert(prev == 0 || svl::detail::validGap(prev, p.wid1));
         m_pWhichRanges[i++] = p.wid1;
         m_pWhichRanges[i++] = p.wid2;
         size += svl::detail::rangeSize(p.wid1, p.wid2);
             // cannot overflow, assuming std::size_t is no smaller than
             // sal_uInt16
-#if !defined NDEBUG
-        //TODO: prev = p.wid2;
-#endif
     }
     m_pWhichRanges[i] = 0;
+    assert(svl::detail::validRanges(m_pWhichRanges));
     m_pItems.reset( new SfxPoolItem const *[size]{} );
 }
 
@@ -178,16 +126,13 @@ SfxItemSet::SfxItemSet( const SfxItemSet& rASet )
     , m_pParent( rASet.m_pParent )
     , m_nCount( rASet.m_nCount )
 {
-    // Calculate the attribute count
-    sal_uInt16 nCnt = 0;
-    sal_uInt16* pPtr = rASet.m_pWhichRanges;
-    while( *pPtr )
+    if (!rASet.m_pWhichRanges)
     {
-        nCnt += ( *(pPtr+1) - *pPtr ) + 1;
-        pPtr += 2;
+        m_pWhichRanges = nullptr;
+        return;
     }
 
-    m_pItems.reset( new const SfxPoolItem* [ nCnt ] );
+    sal_uInt16 nCnt = InitRanges_Impl(rASet.m_pWhichRanges);
 
     // Copy attributes
     SfxPoolItem const** ppDst = m_pItems.get();
@@ -210,10 +155,7 @@ SfxItemSet::SfxItemSet( const SfxItemSet& rASet )
             // !IsPoolable() => assign via Pool
             *ppDst = &m_pPool->Put( **ppSrc );
 
-    // Copy the WhichRanges
-    std::ptrdiff_t cnt = pPtr - rASet.m_pWhichRanges+1;
-    m_pWhichRanges = new sal_uInt16[ cnt ];
-    memcpy( m_pWhichRanges, rASet.m_pWhichRanges, sizeof( sal_uInt16 ) * cnt);
+    assert(svl::detail::validRanges(m_pWhichRanges));
 }
 
 SfxItemSet::SfxItemSet(SfxItemSet&& rASet) noexcept
@@ -227,6 +169,7 @@ SfxItemSet::SfxItemSet(SfxItemSet&& rASet) noexcept
     rASet.m_pParent = nullptr;
     rASet.m_pWhichRanges = nullptr;
     rASet.m_nCount = 0;
+    assert(svl::detail::validRanges(m_pWhichRanges));
 }
 
 SfxItemSet::~SfxItemSet()
@@ -664,67 +607,8 @@ void SfxItemSet::MergeRange( sal_uInt16 nFrom, sal_uInt16 nTo )
             eItemState == SfxItemState::DEFAULT || eItemState == SfxItemState::SET)
             return;
 
-#ifdef DBG_UTIL
-    assert(nFrom <= nTo);
-    for (const sal_uInt16 *pRange = m_pWhichRanges; *pRange; pRange += 2)
-    {
-        assert(pRange[0] <= pRange[1]);
-        // ranges must be sorted and discrete
-        assert(
-            !pRange[2] || (pRange[2] > pRange[1] && pRange[2] - pRange[1] > 1));
-    }
-#endif
-
-    // create vector of ranges (sal_uInt16 pairs of lower and upper bound)
-    const size_t nOldCount = Count_Impl(m_pWhichRanges);
-    std::vector<std::pair<sal_uInt16, sal_uInt16>> aRangesTable;
-    aRangesTable.reserve(nOldCount/2 + 1);
-    bool bAdded = false;
-    for (size_t i = 0; i < nOldCount; i += 2)
-    {
-        if (!bAdded && m_pWhichRanges[i] >= nFrom)
-        {   // insert new range, keep ranges sorted
-            aRangesTable.emplace_back(std::pair<sal_uInt16, sal_uInt16>(nFrom, nTo));
-            bAdded = true;
-        }
-        // insert current range
-        aRangesTable.emplace_back(std::pair<sal_uInt16, sal_uInt16>(m_pWhichRanges[i], m_pWhichRanges[i+1]));
-    }
-    if (!bAdded)
-        aRangesTable.emplace_back(std::pair<sal_uInt16, sal_uInt16>(nFrom, nTo));
-
-    // true if ranges overlap or adjoin, false if ranges are separate
-    auto needMerge = [](std::pair<sal_uInt16, sal_uInt16> lhs, std::pair<sal_uInt16, sal_uInt16> rhs)
-                     {return (lhs.first-1) <= rhs.second && (rhs.first-1) <= lhs.second;};
-
-    std::vector<std::pair<sal_uInt16, sal_uInt16> >::iterator it = aRangesTable.begin();
-    // we got at least one range
-    for (;;)
-    {
-        auto itNext = std::next(it);
-        if (itNext == aRangesTable.end())
-            break;
-        // check neighbouring ranges, find first range which overlaps or adjoins a previous range
-        if (needMerge(*it, *itNext))
-        {
-            // lower bounds are sorted, implies: it->first = min(it[0].first, it[1].first)
-            it->second = std::max(it->second, itNext->second);
-            aRangesTable.erase(itNext);
-        }
-        else
-            ++it;
-    }
-
-    // construct range array
-    const size_t nNewSize = 2 * aRangesTable.size() + 1;
-    std::vector<sal_uInt16> aRanges(nNewSize);
-    for (size_t i = 0; i < (nNewSize - 1); i +=2)
-        std::tie(aRanges[i], aRanges[i+1]) = aRangesTable[i/2];
-
-    // null terminate to be compatible with sal_uInt16* array pointers
-    aRanges.back() = 0;
-
-    SetRanges( aRanges.data() );
+    auto pNewRanges = svl::detail::MergeRange(m_pWhichRanges, nFrom, nTo);
+    SetRanges(pNewRanges.get());
 }
 
 /**
@@ -736,18 +620,21 @@ void SfxItemSet::SetRanges( const sal_uInt16 *pNewRanges )
     // Identical Ranges?
     if (m_pWhichRanges == pNewRanges)
         return;
-    const sal_uInt16* pOld = m_pWhichRanges;
-    const sal_uInt16* pNew = pNewRanges;
-    while ( *pOld == *pNew )
+    if (m_pWhichRanges)
     {
-        if ( !*pOld && !*pNew )
-            return;
-        ++pOld;
-        ++pNew;
+        const sal_uInt16* pOld = m_pWhichRanges;
+        const sal_uInt16* pNew = pNewRanges;
+        while (*pOld == *pNew)
+        {
+            if (!*pOld && !*pNew)
+                return;
+            ++pOld;
+            ++pNew;
+        }
     }
 
     // create new item-array (by iterating through all new ranges)
-    sal_uInt16   nSize = Capacity_Impl(pNewRanges);
+    const auto& [nCount, nSize] = svl::detail::CountRanges(pNewRanges);
     SfxPoolItem const** aNewItems = new const SfxPoolItem* [ nSize ];
     sal_uInt16 nNewCount = 0;
     if (m_nCount == 0)
@@ -807,12 +694,12 @@ void SfxItemSet::SetRanges( const sal_uInt16 *pNewRanges )
     }
     else
     {
-        sal_uInt16 nCount = Count_Impl(pNewRanges) + 1;
         if (m_pWhichRanges != m_pPool->GetFrozenIdRanges())
             delete[] m_pWhichRanges;
         m_pWhichRanges = new sal_uInt16[ nCount ];
         memcpy( m_pWhichRanges, pNewRanges, sizeof( sal_uInt16 ) * nCount );
     }
+    assert(svl::detail::validRanges(m_pWhichRanges));
 }
 
 /**
@@ -907,7 +794,7 @@ const SfxPoolItem& SfxItemSet::Get( sal_uInt16 nWhich, bool bSrchInParent) const
                     {
                         if( IsInvalidItem(*ppFnd) ) {
                             //FIXME: The following code is duplicated further down
-                            SAL_WARN_IF(!m_pPool, "svl.items", "no Pool, but status is ambiguous, with ID/pos " << nWhich);
+                            assert(m_pPool);
                             //!((SfxAllItemSet *)this)->aDefault.SetWhich(nWhich);
                             //!return aDefault;
                             return m_pPool->GetDefaultItem( nWhich );
@@ -934,9 +821,8 @@ const SfxPoolItem& SfxItemSet::Get( sal_uInt16 nWhich, bool bSrchInParent) const
     } while (nullptr != pCurrentSet);
 
     // Get the Default from the Pool and return
-    SAL_WARN_IF(!m_pPool, "svl.items", "no Pool, but status is ambiguous, with ID/pos " << nWhich);
-    const SfxPoolItem *pItem = &m_pPool->GetDefaultItem( nWhich );
-    return *pItem;
+    assert(m_pPool);
+    return m_pPool->GetDefaultItem( nWhich );
 }
 
 /**
@@ -1514,19 +1400,12 @@ void SfxItemSet::dumpAsXml(xmlTextWriterPtr pWriter) const
 // ----------------------------------------------- class SfxAllItemSet
 
 SfxAllItemSet::SfxAllItemSet( SfxItemPool &rPool )
-:   SfxItemSet(rPool, nullptr),
-    nFree(nInitCount)
+:   SfxItemSet(rPool, nullptr)
 {
-    // Initially no Items
-    m_pItems = nullptr;
-
-    // Allocate nInitCount pairs at USHORTs for Ranges
-    m_pWhichRanges = new sal_uInt16[nInitCount + 1]{};
 }
 
 SfxAllItemSet::SfxAllItemSet(const SfxItemSet &rCopy)
-:   SfxItemSet(rCopy),
-    nFree(0)
+:   SfxItemSet(rCopy)
 {
 }
 
@@ -1535,66 +1414,8 @@ SfxAllItemSet::SfxAllItemSet(const SfxItemSet &rCopy)
  * The compiler does not take the ctor with the 'const SfxItemSet&'!
  */
 SfxAllItemSet::SfxAllItemSet(const SfxAllItemSet &rCopy)
-:   SfxItemSet(rCopy),
-    nFree(0)
-{
-}
-
-/**
- * This internal function creates a new WhichRanges array, which is copied
- * from the 'nOldSize'-USHORTs long 'pUS'. It has new USHORTs at the end instead
- * of 'nIncr'.
- * The terminating sal_uInt16 with the '0' is neither accounted for in 'nOldSize'
- * nor in 'nIncr', but always explicitly added.
- *
- * @returns the new WhichRanges array (the old 'pUS' is freed)
- */
-static sal_uInt16 *AddRanges_Impl(
-    sal_uInt16 *pUS, std::ptrdiff_t nOldSize, sal_uInt16 nIncr)
+:   SfxItemSet(rCopy)
 {
-    // Create new WhichRanges array
-    sal_uInt16 *pNew = new sal_uInt16[ nOldSize + nIncr + 1 ];
-
-    // Take over the old Ranges
-    memcpy( pNew, pUS, nOldSize * sizeof(sal_uInt16) );
-
-    // Initialize the new one to 0
-    memset( pNew + nOldSize, 0, ( nIncr + 1 ) * sizeof(sal_uInt16) );
-
-    // Free the old array
-    delete[] pUS;
-
-    return pNew;
-}
-
-/**
- * This internal function creates a new ItemArray, which is copied from 'pItems',
- * but has room for a new ItemPointer at 'nPos'.
- *
- * @returns the new ItemArray (the old 'pItems' is freed)
- */
-static void AddItem_Impl(std::unique_ptr<SfxPoolItem const*[]> & rpItems, sal_uInt16 nOldSize, sal_uInt16 nPos)
-{
-    // Create new ItemArray
-    SfxPoolItem const** pNew = new const SfxPoolItem*[nOldSize+1];
-
-    // Was there one before?
-    if ( rpItems )
-    {
-        // Copy all Items before nPos
-        if ( nPos )
-            memcpy( static_cast<void*>(pNew), rpItems.get(), nPos * sizeof(SfxPoolItem *) );
-
-        // Copy all Items after nPos
-        if ( nPos < nOldSize )
-            memcpy( static_cast<void*>(pNew + nPos + 1), rpItems.get() + nPos,
-                    (nOldSize-nPos) * sizeof(SfxPoolItem *) );
-    }
-
-    // Initialize new Item
-    *(pNew + nPos) = nullptr;
-
-    rpItems.reset(pNew);
 }
 
 /**
@@ -1602,122 +1423,8 @@ static void AddItem_Impl(std::unique_ptr<SfxPoolItem const*[]> & rpItems, sal_uI
  */
 const SfxPoolItem* SfxAllItemSet::PutImpl( const SfxPoolItem& rItem, sal_uInt16 nWhich, bool bPassingOwnership )
 {
-    sal_uInt16 nPos = 0; // Position for 'rItem' in 'm_pItems'
-    const sal_uInt16 nItemCount = TotalCount();
-
-    // Let's see first whether there's a suitable Range already
-    sal_uInt16 *pPtr = m_pWhichRanges;
-    while ( *pPtr )
-    {
-        // WhichId is within this Range?
-        if( *pPtr <= nWhich && nWhich <= *(pPtr+1) )
-        {
-            // Insert
-            nPos += nWhich - *pPtr;
-            break;
-        }
-
-        // Carry over the position of the Item in m_pItems
-        nPos += *(pPtr+1) - *pPtr + 1;
-
-        // To the next Range
-        pPtr += 2;
-    }
-
-    // WhichId not yet present?
-    if ( !*pPtr )
-    {
-        // Let's see if we can attach it somewhere
-        pPtr = m_pWhichRanges;
-        nPos = 0;
-        while ( *pPtr )
-        {
-            // WhichId is right before this Range?
-            if ( (nWhich+1) == *pPtr )
-            {
-                // Range grows downwards
-                (*pPtr)--;
-
-                // Make room before first Item of this Range
-                AddItem_Impl(m_pItems, nItemCount, nPos);
-                break;
-            }
-
-            // WhichId is right after this Range?
-            else if ( (nWhich-1) == *(pPtr+1) )
-            {
-                // Range grows upwards?
-                (*(pPtr+1))++;
-
-                // Make room after last Item of this Range
-                nPos += nWhich - *pPtr;
-                AddItem_Impl(m_pItems, nItemCount, nPos);
-                break;
-            }
-
-            // Carry over position of the Item in m_pItems
-            nPos += *(pPtr+1) - *pPtr + 1;
-
-            // To the next Range
-            pPtr += 2;
-        }
-    }
-
-    // No extensible Range found?
-    if ( !*pPtr )
-    {
-        // No room left in m_pWhichRanges? => Expand!
-        std::ptrdiff_t nSize = pPtr - m_pWhichRanges;
-        if( !nFree )
-        {
-            m_pWhichRanges = AddRanges_Impl(m_pWhichRanges, nSize, nInitCount);
-            nFree += nInitCount;
-        }
-
-        // Attach new WhichRange
-        pPtr = m_pWhichRanges + nSize;
-        *pPtr++ = nWhich;
-        *pPtr = nWhich;
-        nFree -= 2;
-
-        // Expand ItemArray
-        nPos = nItemCount;
-        AddItem_Impl(m_pItems, nItemCount, nPos);
-    }
-
-    // Add new Item to Pool
-    const SfxPoolItem& rNew = m_pPool->PutImpl( rItem, nWhich, bPassingOwnership );
-
-    // Remember old Item
-    bool bIncrementCount = false;
-    const SfxPoolItem* pOld = m_pItems[nPos];
-    if ( IsInvalidItem(pOld) ) // state "dontcare"
-        pOld = nullptr;
-    if ( !pOld )
-    {
-        bIncrementCount = true;
-        pOld = m_pParent
-            ? &m_pParent->Get( nWhich )
-            : (SfxItemPool::IsWhich(nWhich)
-                    ? &m_pPool->GetDefaultItem(nWhich)
-                    : nullptr);
-    }
-
-    // Add new Item to ItemSet
-    m_pItems[nPos] = &rNew;
-
-    // Send Changed Notification
-    if ( pOld )
-    {
-        Changed( *pOld, rNew );
-        if ( !IsDefaultItem(pOld) )
-            m_pPool->Remove( *pOld );
-    }
-
-    if ( bIncrementCount )
-        ++m_nCount;
-
-    return &rNew;
+    MergeRange(nWhich, nWhich);
+    return SfxItemSet::PutImpl(rItem, nWhich, bPassingOwnership);
 }
 
 /**
diff --git a/svx/source/dialog/hdft.cxx b/svx/source/dialog/hdft.cxx
index 06605ce2efcf..de65ff6c5d01 100644
--- a/svx/source/dialog/hdft.cxx
+++ b/svx/source/dialog/hdft.cxx
@@ -202,30 +202,25 @@ bool SvxHFPage::FillItemSet( SfxItemSet* rSet )
     const sal_uInt16 nWBoxInfo = GetWhich(SID_ATTR_BORDER_INNER);
     const sal_uInt16 nWShadow = GetWhich(SID_ATTR_BORDER_SHADOW);
 
-    const sal_uInt16 aWhichTab[] = {
-        nWSize, nWSize,
-        nWLRSpace, nWLRSpace,
-        nWULSpace, nWULSpace,
-        nWOn, nWOn,
-        nWDynamic, nWDynamic,
-        nWShared, nWShared,
-        nWSharedFirst, nWSharedFirst,
-        nWBrush, nWBrush,
-        nWBoxInfo, nWBoxInfo,
-        nWBox, nWBox,
-        nWShadow, nWShadow,
-        nWDynSpacing, nWDynSpacing,
-
-        // take over DrawingLayer FillStyles
-        XATTR_FILL_FIRST, XATTR_FILL_LAST,                // [1014
-
-        0, 0};
-
     const SfxItemSet& rOldSet = GetItemSet();
     SfxItemPool* pPool = rOldSet.GetPool();
     DBG_ASSERT(pPool,"no pool :-(");
     MapUnit eUnit = pPool->GetMetric(nWSize);
-    SfxItemSet aSet(*pPool,aWhichTab);
+    // take over DrawingLayer FillStyles
+    SfxItemSet aSet(*pPool, svl::Items<XATTR_FILL_FIRST, XATTR_FILL_LAST>{});
+    // Keep it valid
+    aSet.MergeRange(nWSize, nWSize);
+    aSet.MergeRange(nWLRSpace, nWLRSpace);
+    aSet.MergeRange(nWULSpace, nWULSpace);
+    aSet.MergeRange(nWOn, nWOn);
+    aSet.MergeRange(nWDynamic, nWDynamic);
+    aSet.MergeRange(nWShared, nWShared);
+    aSet.MergeRange(nWSharedFirst, nWSharedFirst);
+    aSet.MergeRange(nWBrush, nWBrush);
+    aSet.MergeRange(nWBoxInfo, nWBoxInfo);
+    aSet.MergeRange(nWBox, nWBox);
+    aSet.MergeRange(nWShadow, nWShadow);
+    aSet.MergeRange(nWDynSpacing, nWDynSpacing);
 
     if(mbEnableDrawingLayerFillStyles)
     {
@@ -540,11 +535,12 @@ IMPL_LINK_NOARG(SvxHFPage, BackgroundHdl, weld::Button&, void)
         {
             pBBSet.reset(new SfxItemSet(
                 *GetItemSet().GetPool(),
-                {{XATTR_FILL_FIRST, XATTR_FILL_LAST},  // DrawingLayer FillStyle definitions
-                {SID_COLOR_TABLE, SID_PATTERN_LIST},   // XPropertyLists for Color, Gradient, Hatch and Graphic fills
-                {nOuter, nOuter},
-                {nInner, nInner},
-                {nShadow, nShadow}}));
+                svl::Items<XATTR_FILL_FIRST, XATTR_FILL_LAST,      // DrawingLayer FillStyle definitions
+                           SID_COLOR_TABLE, SID_PATTERN_LIST>{})); // XPropertyLists for Color, Gradient, Hatch and Graphic fills
+            // Keep it valid
+            pBBSet->MergeRange(nOuter, nOuter);
+            pBBSet->MergeRange(nInner, nInner);
+            pBBSet->MergeRange(nShadow, nShadow);
 
             // copy items for XPropertyList entries from the DrawModel so that
             // the Area TabPage can access them
@@ -577,11 +573,12 @@ IMPL_LINK_NOARG(SvxHFPage, BackgroundHdl, weld::Button&, void)
 
             pBBSet.reset( new SfxItemSet(
                 *GetItemSet().GetPool(),
-                {{XATTR_FILL_FIRST, XATTR_FILL_LAST},
-                {nBrush, nBrush},
-                {nOuter, nOuter},
-                {nInner, nInner},
-                {nShadow, nShadow}}) );
+                svl::Items<XATTR_FILL_FIRST, XATTR_FILL_LAST>{}) );
+            // Keep it valid
+            pBBSet->MergeRange(nBrush, nBrush);
+            pBBSet->MergeRange(nOuter, nOuter);
+            pBBSet->MergeRange(nInner, nInner);
+            pBBSet->MergeRange(nShadow, nShadow);
         }
 
         const SfxPoolItem* pItem;
diff --git a/svx/source/svdraw/svdedxv.cxx b/svx/source/svdraw/svdedxv.cxx
index 58d8437b9513..1bf140367ac1 100644
--- a/svx/source/svdraw/svdedxv.cxx
+++ b/svx/source/svdraw/svdedxv.cxx
@@ -2629,25 +2629,21 @@ bool SdrObjEditView::SupportsFormatPaintbrush(SdrInventor nObjectInventor,
 
 static const sal_uInt16* GetFormatRangeImpl(bool bTextOnly)
 {
-    static const sal_uInt16 gRanges[] = { SDRATTR_SHADOW_FIRST,
-                                          SDRATTR_SHADOW_LAST,
-                                          SDRATTR_GRAF_FIRST,
-                                          SDRATTR_GRAF_LAST,
-                                          SDRATTR_TABLE_FIRST,
-                                          SDRATTR_TABLE_LAST,
-                                          XATTR_LINE_FIRST,
-                                          XATTR_LINE_LAST,
-                                          XATTR_FILL_FIRST,
-                                          XATTRSET_FILL,
-                                          EE_PARA_START,
-                                          EE_PARA_END, // text-only from here on
-                                          EE_CHAR_START,
-                                          EE_CHAR_END,
-                                          SDRATTR_MISC_FIRST,
-                                          SDRATTR_MISC_LAST, // table cell formats
-                                          0,
-                                          0 };
-    return &gRanges[bTextOnly ? 10 : 0];
+    static constexpr auto gFull
+        = svl::ItemsArray({ { XATTR_LINE_FIRST, XATTR_LINE_LAST },
+                            { XATTR_FILL_FIRST, XATTRSET_FILL },
+                            { SDRATTR_SHADOW_FIRST, SDRATTR_SHADOW_LAST },
+                            { SDRATTR_MISC_FIRST, SDRATTR_MISC_LAST }, // table cell formats
+                            { SDRATTR_GRAF_FIRST, SDRATTR_GRAF_LAST },
+                            { SDRATTR_TABLE_FIRST, SDRATTR_TABLE_LAST },
+                            { EE_PARA_START, EE_PARA_END },
+                            { EE_CHAR_START, EE_CHAR_END } });
+
+    static constexpr auto gTextOnly = svl::ItemsArray({ { SDRATTR_MISC_FIRST, SDRATTR_MISC_LAST },
+                                                        { EE_PARA_START, EE_PARA_END },
+                                                        { EE_CHAR_START, EE_CHAR_END } });
+
+    return bTextOnly ? gTextOnly.data() : gFull.data();
 }
 
 void SdrObjEditView::TakeFormatPaintBrush(std::shared_ptr<SfxItemSet>& rFormatSet)
diff --git a/sw/source/core/bastyp/init.cxx b/sw/source/core/bastyp/init.cxx
index 1d59814cd810..cb7de9e860e0 100644
--- a/sw/source/core/bastyp/init.cxx
+++ b/sw/source/core/bastyp/init.cxx
@@ -147,9 +147,9 @@ sal_uInt16 const aBreakSetRange[] = {
 // list attributes ( RES_PARATR_LIST_BEGIN - RES_PARATR_LIST_END ) are not
 // included in the paragraph style's itemset.
 sal_uInt16 const aTextFormatCollSetRange[] = {
-    RES_FRMATR_BEGIN, RES_FRMATR_END-1,
     RES_CHRATR_BEGIN, RES_CHRATR_END-1,
     RES_PARATR_BEGIN, RES_PARATR_END-1,
+    RES_FRMATR_BEGIN, RES_FRMATR_END-1,
     RES_UNKNOWNATR_BEGIN, RES_UNKNOWNATR_END-1,
 
     // FillAttribute support
@@ -168,10 +168,10 @@ sal_uInt16 const aGrfFormatCollSetRange[] = {
 
 // AttrSet range for TextNode
 sal_uInt16 const aTextNodeSetRange[] = {
-    RES_FRMATR_BEGIN, RES_FRMATR_END-1,
     RES_CHRATR_BEGIN, RES_CHRATR_END-1,
     RES_PARATR_BEGIN, RES_PARATR_END-1,
     RES_PARATR_LIST_BEGIN, RES_PARATR_LIST_END-1,
+    RES_FRMATR_BEGIN, RES_FRMATR_END-1,
     RES_UNKNOWNATR_BEGIN, RES_UNKNOWNATR_END-1,
 
     // FillAttribute support (paragraph FillStyle)
@@ -191,41 +191,41 @@ sal_uInt16 const aNoTextNodeSetRange[] = {
 sal_uInt16 const aTableSetRange[] = {
     RES_FILL_ORDER,     RES_FRM_SIZE,
     RES_LR_SPACE,       RES_BREAK,
-    RES_BACKGROUND,     RES_SHADOW,
     RES_HORI_ORIENT,    RES_HORI_ORIENT,
+    RES_BACKGROUND,     RES_SHADOW,
     RES_KEEP,           RES_KEEP,
     RES_LAYOUT_SPLIT,   RES_LAYOUT_SPLIT,
     RES_FRAMEDIR,       RES_FRAMEDIR,
     // #i29550#
     RES_COLLAPSING_BORDERS, RES_COLLAPSING_BORDERS,
     // <-- collapsing
-    RES_UNKNOWNATR_BEGIN, RES_UNKNOWNATR_END-1,
     RES_FRMATR_GRABBAG, RES_FRMATR_GRABBAG,
+    RES_UNKNOWNATR_BEGIN, RES_UNKNOWNATR_END-1,
     0
 };
 
 sal_uInt16 const aTableLineSetRange[] = {
     RES_FILL_ORDER,     RES_FRM_SIZE,
     RES_LR_SPACE,       RES_UL_SPACE,
-    RES_BACKGROUND,     RES_SHADOW,
-    RES_ROW_SPLIT,      RES_ROW_SPLIT,
     RES_PROTECT,        RES_PROTECT,
     RES_VERT_ORIENT,    RES_VERT_ORIENT,
-    RES_UNKNOWNATR_BEGIN, RES_UNKNOWNATR_END-1,
+    RES_BACKGROUND,     RES_SHADOW,
+    RES_ROW_SPLIT,      RES_ROW_SPLIT,
     RES_FRMATR_GRABBAG, RES_FRMATR_GRABBAG,
+    RES_UNKNOWNATR_BEGIN, RES_UNKNOWNATR_END-1,
     0
 };
 
 sal_uInt16 const aTableBoxSetRange[] = {
     RES_FILL_ORDER,     RES_FRM_SIZE,
     RES_LR_SPACE,       RES_UL_SPACE,
-    RES_BACKGROUND,     RES_SHADOW,
     RES_PROTECT,        RES_PROTECT,
     RES_VERT_ORIENT,    RES_VERT_ORIENT,
+    RES_BACKGROUND,     RES_SHADOW,
     RES_FRAMEDIR,       RES_FRAMEDIR,
+    RES_FRMATR_GRABBAG, RES_FRMATR_GRABBAG,
     RES_BOXATR_BEGIN,   RES_BOXATR_END-1,
     RES_UNKNOWNATR_BEGIN, RES_UNKNOWNATR_END-1,
-    RES_FRMATR_GRABBAG, RES_FRMATR_GRABBAG,
     0
 };
 
diff --git a/sw/source/core/doc/docnew.cxx b/sw/source/core/doc/docnew.cxx
index 3380b5e6bc15..bee045a5757c 100644
--- a/sw/source/core/doc/docnew.cxx
+++ b/sw/source/core/doc/docnew.cxx
@@ -842,10 +842,10 @@ void SwDoc::ReplaceDefaults(const SwDoc& rSource)
     // copy property defaults
     const sal_uInt16 aRangeOfDefaults[] =
     {
-        RES_FRMATR_BEGIN, RES_FRMATR_END-1,
         RES_CHRATR_BEGIN, RES_CHRATR_END-1,
         RES_PARATR_BEGIN, RES_PARATR_END-1,
         RES_PARATR_LIST_BEGIN, RES_PARATR_LIST_END-1,
+        RES_FRMATR_BEGIN, RES_FRMATR_END-1,
         RES_UNKNOWNATR_BEGIN, RES_UNKNOWNATR_END-1,
         XATTR_START, XATTR_END-1,
         0
diff --git a/sw/source/core/docnode/ndtbl.cxx b/sw/source/core/docnode/ndtbl.cxx
index acca43916522..f30ebce4c0f8 100644
--- a/sw/source/core/docnode/ndtbl.cxx
+++ b/sw/source/core/docnode/ndtbl.cxx
@@ -3044,15 +3044,11 @@ void sw_BoxSetSplitBoxFormats( SwTableBox* pBox, SwCollectTableLineBoxes* pSplPa
         }
         else
         {
-            sal_uInt16 const aTableSplitBoxSetRange[] {
-                RES_LR_SPACE,       RES_UL_SPACE,
-                RES_BACKGROUND,     RES_SHADOW,
-                RES_PROTECT,        RES_PROTECT,
-                RES_VERT_ORIENT,    RES_VERT_ORIENT,
-                0 };
-
             SfxItemSet aTmpSet( pFormat->GetDoc()->GetAttrPool(),
-                                aTableSplitBoxSetRange );
+                                svl::Items<RES_LR_SPACE,    RES_UL_SPACE,
+                                           RES_PROTECT,     RES_PROTECT,
+                                           RES_VERT_ORIENT, RES_VERT_ORIENT,
+                                           RES_BACKGROUND,  RES_SHADOW>{} );
             aTmpSet.Put( pFormat->GetAttrSet() );
             if( aTmpSet.Count() )
                 pBox->ClaimFrameFormat()->SetFormatAttr( aTmpSet );
diff --git a/sw/source/core/fields/expfld.cxx b/sw/source/core/fields/expfld.cxx
index 0e486a2963e1..4825335540b8 100644
--- a/sw/source/core/fields/expfld.cxx
+++ b/sw/source/core/fields/expfld.cxx
@@ -983,13 +983,13 @@ sal_Int32 SwGetExpField::GetReferenceTextPos( const SwFormatField& rFormat, SwDo
 
         static const sal_uInt16 nIds[] =
         {
-            RES_CHRATR_LANGUAGE, RES_CHRATR_LANGUAGE,
             RES_CHRATR_FONT, RES_CHRATR_FONT,
-            RES_CHRATR_CJK_LANGUAGE, RES_CHRATR_CJK_LANGUAGE,
+            RES_CHRATR_LANGUAGE, RES_CHRATR_LANGUAGE,
             RES_CHRATR_CJK_FONT, RES_CHRATR_CJK_FONT,
-            RES_CHRATR_CTL_LANGUAGE, RES_CHRATR_CTL_LANGUAGE,
+            RES_CHRATR_CJK_LANGUAGE, RES_CHRATR_CJK_LANGUAGE,
             RES_CHRATR_CTL_FONT, RES_CHRATR_CTL_FONT,
-            0, 0
+            RES_CHRATR_CTL_LANGUAGE, RES_CHRATR_CTL_LANGUAGE,
+            0
         };
         SwAttrSet aSet(rDoc.GetAttrPool(), nIds);
         rTextNode.GetParaAttr(aSet, nRet, nRet+1);
diff --git a/sw/source/core/txtnode/txtedt.cxx b/sw/source/core/txtnode/txtedt.cxx
index 61e1101fb330..82325abed03a 100644
--- a/sw/source/core/txtnode/txtedt.cxx
+++ b/sw/source/core/txtnode/txtedt.cxx
@@ -1070,15 +1070,10 @@ void SwTextNode::SetLanguageAndFont( const SwPaM &rPaM,
     LanguageType nLang, sal_uInt16 nLangWhichId,
     const vcl::Font *pFont,  sal_uInt16 nFontWhichId )
 {
-    sal_uInt16 aRanges[] = {
-            nLangWhichId, nLangWhichId,
-            nFontWhichId, nFontWhichId,
-            0, 0, 0 };
-    if (!pFont)
-        aRanges[2] = aRanges[3] = 0;    // clear entries with font WhichId
-
     SwEditShell *pEditShell = GetDoc().GetEditShell();
-    SfxItemSet aSet( pEditShell->GetAttrPool(), aRanges );
+    SfxItemSet aSet(pEditShell->GetAttrPool(), { { nLangWhichId, nLangWhichId } });
+    if (pFont)
+        aSet.MergeRange(nFontWhichId, nFontWhichId); // Keep it sorted
     aSet.Put( SvxLanguageItem( nLang, nLangWhichId ) );
 
     OSL_ENSURE( pFont, "target font missing?" );
diff --git a/sw/source/core/unocore/unocrsrhelper.cxx b/sw/source/core/unocore/unocrsrhelper.cxx
index 8c09a63113fa..e7a5944427dc 100644
--- a/sw/source/core/unocore/unocrsrhelper.cxx
+++ b/sw/source/core/unocore/unocrsrhelper.cxx
@@ -1293,7 +1293,7 @@ void makeRedline( SwPaM const & rPaM,
             SwDoc& rDoc = rPaM.GetDoc();
 
             // Build set of attributes we want to fetch
-            std::vector<sal_uInt16> aWhichPairs;
+            std::vector<std::pair<sal_uInt16, sal_uInt16>> aWhichPairs;
             std::vector<SfxItemPropertySimpleEntry const*> aEntries;
             std::vector<uno::Any> aValues;
             aEntries.reserve(aRevertProperties.getLength());
@@ -1315,15 +1315,12 @@ void makeRedline( SwPaM const & rPaM,
                 }
                 else if (rPropertyName == "NumberingRules")
                 {
-                    aWhichPairs.push_back(RES_PARATR_NUMRULE);
-                    aWhichPairs.push_back(RES_PARATR_NUMRULE);
+                    aWhichPairs.emplace_back(RES_PARATR_NUMRULE, RES_PARATR_NUMRULE);
                     nNumId = aEntries.size();
                 }
                 else
                 {
-                    // FIXME: we should have some nice way of merging ranges surely ?
-                    aWhichPairs.push_back(pEntry->nWID);
-                    aWhichPairs.push_back(pEntry->nWID);
+                    aWhichPairs.emplace_back(pEntry->nWID, pEntry->nWID);
                     if (rPropertyName == "ParaStyleName")
                         nStyleId = aEntries.size();
                 }
@@ -1335,8 +1332,9 @@ void makeRedline( SwPaM const & rPaM,
             {
                 sal_uInt16 nStylePoolId = USHRT_MAX;
                 OUString sParaStyleName;
-                aWhichPairs.push_back(0); // terminate
-                SfxItemSet aItemSet(rDoc.GetAttrPool(), aWhichPairs.data());
+                SfxItemSet aItemSet(rDoc.GetAttrPool(), nullptr);
+                for (const auto& [nWhich1, nWhich2] : aWhichPairs)
+                    aItemSet.MergeRange(nWhich1, nWhich2);
 
                 for (size_t i = 0; i < aEntries.size(); ++i)
                 {
diff --git a/sw/source/uibase/app/docshini.cxx b/sw/source/uibase/app/docshini.cxx
index f4aadf7476ca..5700c643508c 100644
--- a/sw/source/uibase/app/docshini.cxx
+++ b/sw/source/uibase/app/docshini.cxx
@@ -624,11 +624,11 @@ void SwDocShell::SubInitNew()
     bool bWeb = dynamic_cast< const SwWebDocShell *>( this ) !=  nullptr;
 
     sal_uInt16 nRange[] =   {
-        RES_PARATR_ADJUST, RES_PARATR_ADJUST,
         RES_CHRATR_COLOR, RES_CHRATR_COLOR,
         RES_CHRATR_LANGUAGE, RES_CHRATR_LANGUAGE,
         RES_CHRATR_CJK_LANGUAGE, RES_CHRATR_CJK_LANGUAGE,
         RES_CHRATR_CTL_LANGUAGE, RES_CHRATR_CTL_LANGUAGE,
+        RES_PARATR_ADJUST, RES_PARATR_ADJUST,
         0, 0, 0  };
     if(!bWeb)
     {
diff --git a/sw/source/uibase/lingu/hhcwrp.cxx b/sw/source/uibase/lingu/hhcwrp.cxx
index 23974dfa109a..f724ed377119 100644
--- a/sw/source/uibase/lingu/hhcwrp.cxx
+++ b/sw/source/uibase/lingu/hhcwrp.cxx
@@ -466,12 +466,9 @@ void SwHHCWrapper::ReplaceUnit(
             OSL_ENSURE( GetTargetLanguage() == LANGUAGE_CHINESE_SIMPLIFIED || GetTargetLanguage() == LANGUAGE_CHINESE_TRADITIONAL,
                     "SwHHCWrapper::ReplaceUnit : unexpected target language" );
 
-            sal_uInt16 const aRanges[] {
-                    RES_CHRATR_CJK_LANGUAGE, RES_CHRATR_CJK_LANGUAGE,
+            SfxItemSet aSet( m_rWrtShell.GetAttrPool(), svl::Items<
                     RES_CHRATR_CJK_FONT,     RES_CHRATR_CJK_FONT,
-                    0, 0, 0  };
-
-            SfxItemSet aSet( m_rWrtShell.GetAttrPool(), aRanges );
+                    RES_CHRATR_CJK_LANGUAGE, RES_CHRATR_CJK_LANGUAGE>{} );
             if (pNewUnitLanguage)
             {
                 aSet.Put( SvxLanguageItem( *pNewUnitLanguage, RES_CHRATR_CJK_LANGUAGE ) );
diff --git a/sw/source/uibase/shells/tabsh.cxx b/sw/source/uibase/shells/tabsh.cxx
index 82c382b6fe36..c0c4d58d5690 100644
--- a/sw/source/uibase/shells/tabsh.cxx
+++ b/sw/source/uibase/shells/tabsh.cxx
@@ -95,29 +95,29 @@ void SwTableShell::InitInterface_Impl()
 
 const sal_uInt16 aUITableAttrRange[] =
 {
-    XATTR_FILL_FIRST,               XATTR_FILL_LAST,
-    FN_PARAM_TABLE_NAME,            FN_PARAM_TABLE_NAME,
-    FN_PARAM_TABLE_HEADLINE,        FN_PARAM_TABLE_HEADLINE,
-    FN_PARAM_TABLE_SPACE,           FN_PARAM_TABLE_SPACE,
-    FN_TABLE_REP,                   FN_TABLE_REP,
-    SID_RULER_BORDERS,              SID_RULER_BORDERS,
     RES_LR_SPACE,                   RES_UL_SPACE,
-    SID_ATTR_BORDER_INNER,          SID_ATTR_BORDER_SHADOW,
-    RES_BOX,                        RES_SHADOW,
-    RES_BACKGROUND,                 RES_BACKGROUND,
-    SID_BACKGRND_DESTINATION,       SID_BACKGRND_DESTINATION,
-    SID_HTML_MODE,                  SID_HTML_MODE,
-    SID_ATTR_BRUSH_ROW,             SID_ATTR_BRUSH_TABLE,
     RES_PAGEDESC,                   RES_BREAK,
+    RES_BACKGROUND,                 RES_BACKGROUND,
+    RES_BOX,                        RES_SHADOW,
     RES_KEEP,                       RES_KEEP,
     RES_LAYOUT_SPLIT,               RES_LAYOUT_SPLIT,
-    FN_TABLE_SET_VERT_ALIGN,        FN_TABLE_SET_VERT_ALIGN,
     RES_FRAMEDIR,                   RES_FRAMEDIR,
     RES_ROW_SPLIT,                  RES_ROW_SPLIT,
-    FN_TABLE_BOX_TEXTORIENTATION,   FN_TABLE_BOX_TEXTORIENTATION,
 // #i29550#
     RES_COLLAPSING_BORDERS,         RES_COLLAPSING_BORDERS,
 // <-- collapsing borders
+    XATTR_FILL_FIRST,               XATTR_FILL_LAST,
+    SID_ATTR_BORDER_INNER,          SID_ATTR_BORDER_SHADOW,
+    SID_RULER_BORDERS,              SID_RULER_BORDERS,
+    SID_ATTR_BRUSH_ROW,             SID_ATTR_BRUSH_TABLE, // ??? This is very strange range
+//  SID_BACKGRND_DESTINATION,       SID_BACKGRND_DESTINATION, // included into above
+//  SID_HTML_MODE,                  SID_HTML_MODE, // included into above
+    FN_TABLE_REP,                   FN_TABLE_REP,
+    FN_TABLE_SET_VERT_ALIGN,        FN_TABLE_SET_VERT_ALIGN,
+    FN_TABLE_BOX_TEXTORIENTATION,   FN_TABLE_BOX_TEXTORIENTATION,
+    FN_PARAM_TABLE_NAME,            FN_PARAM_TABLE_NAME,
+    FN_PARAM_TABLE_HEADLINE,        FN_PARAM_TABLE_HEADLINE,
+    FN_PARAM_TABLE_SPACE,           FN_PARAM_TABLE_SPACE,
     0
 };
 
diff --git a/sw/source/uibase/shells/textsh.cxx b/sw/source/uibase/shells/textsh.cxx
index daa913816a63..9c942b7858cd 100644
--- a/sw/source/uibase/shells/textsh.cxx
+++ b/sw/source/uibase/shells/textsh.cxx
@@ -836,20 +836,15 @@ SwTextShell::~SwTextShell()
 
 SfxItemSet SwTextShell::CreateInsertFrameItemSet(SwFlyFrameAttrMgr& rMgr)
 {
-    static const sal_uInt16 aFrameAttrRange[] =
-    {
+    SfxItemSet aSet(GetPool(), svl::Items<
         RES_FRMATR_BEGIN,       RES_FRMATR_END-1,
+        XATTR_FILL_FIRST,       XATTR_FILL_LAST, // tdf#95003
         SID_ATTR_BORDER_INNER,  SID_ATTR_BORDER_INNER,
-        FN_GET_PRINT_AREA,      FN_GET_PRINT_AREA,
         SID_ATTR_PAGE_SIZE,     SID_ATTR_PAGE_SIZE,
-        FN_SET_FRM_NAME,        FN_SET_FRM_NAME,
-        SID_HTML_MODE,          SID_HTML_MODE,
         SID_COLOR_TABLE,        SID_PATTERN_LIST,
-        XATTR_FILL_FIRST,       XATTR_FILL_LAST, // tdf#95003
-        0
-    };
-
-    SfxItemSet aSet(GetPool(), aFrameAttrRange );
+        SID_HTML_MODE,          SID_HTML_MODE,
+        FN_GET_PRINT_AREA,      FN_GET_PRINT_AREA,
+        FN_SET_FRM_NAME,        FN_SET_FRM_NAME>{});
     aSet.Put(SfxUInt16Item(SID_HTML_MODE, ::GetHtmlMode(GetView().GetDocShell())));
 
     // For the Area tab page.
diff --git a/sw/source/uibase/uiview/viewsrch.cxx b/sw/source/uibase/uiview/viewsrch.cxx
index 578d02f296d4..a0cd2967fad5 100644
--- a/sw/source/uibase/uiview/viewsrch.cxx
+++ b/sw/source/uibase/uiview/viewsrch.cxx
@@ -740,9 +740,9 @@ sal_uLong SwView::FUNC_Search( const SwSearchOptions& rOptions )
     m_pWrtShell->SttSelect();
 
     static const sal_uInt16 aSearchAttrRange[] = {
-        RES_FRMATR_BEGIN, RES_FRMATR_END-1,
         RES_CHRATR_BEGIN, RES_CHRATR_END-1,
         RES_PARATR_BEGIN, RES_PARATR_END-1,
+        RES_FRMATR_BEGIN, RES_FRMATR_END-1,
         SID_ATTR_PARA_MODEL, SID_ATTR_PARA_KEEP,
         0 };
 
diff --git a/sw/source/uibase/uno/SwXDocumentSettings.cxx b/sw/source/uibase/uno/SwXDocumentSettings.cxx
index 19dabb9ea6b8..2643071e13dd 100644
--- a/sw/source/uibase/uno/SwXDocumentSettings.cxx
+++ b/sw/source/uibase/uno/SwXDocumentSettings.cxx
@@ -449,15 +449,11 @@ void SwXDocumentSettings::_setSingleValue( const comphelper::PropertyInfo & rInf
                 SvMemoryStream aStream (aSequence.getArray(), nSize,
                                         StreamMode::READ );
                 aStream.Seek ( STREAM_SEEK_TO_BEGIN );
-                static sal_uInt16 const nRange[] =
-                {
-                    FN_PARAM_ADDPRINTER, FN_PARAM_ADDPRINTER,
-                    SID_HTML_MODE,  SID_HTML_MODE,
+                auto pItemSet = std::make_unique<SfxItemSet>( mpDoc->GetAttrPool(), svl::Items<
                     SID_PRINTER_NOTFOUND_WARN, SID_PRINTER_NOTFOUND_WARN,
                     SID_PRINTER_CHANGESTODOC, SID_PRINTER_CHANGESTODOC,
-                    0
-                };
-                auto pItemSet = std::make_unique<SfxItemSet>( mpDoc->GetAttrPool(), nRange );
+                    SID_HTML_MODE,  SID_HTML_MODE,
+                    FN_PARAM_ADDPRINTER, FN_PARAM_ADDPRINTER>{} );
                 VclPtr<SfxPrinter> pPrinter = SfxPrinter::Create ( aStream, std::move(pItemSet) );
                 assert (! pPrinter->isDisposed() );
                 // set printer only once; in _postSetValues