sw user field type: fix locale of string -> float conversion

The key part is the SwUserFieldType::GetValue() hunk, the field type has
to always use the same locale, which means if we get an SwCalc reference
that works with the document or field locale that has to be switched
temporarily.

Reviewed-on: https://gerrit.libreoffice.org/58492
Reviewed-by: Miklos Vajna <vmiklos@collabora.co.uk>
Tested-by: Jenkins
(cherry picked from commit 6ca5d288ca810f128163da121777ee2e11c46edc)

Conflicts:
	sw/qa/extras/layout/layout.cxx
	sw/source/core/fields/usrfld.cxx

Change-Id: I26ff18e74f477729a66b066c4baf6d215a7685bc

8 files changed, 204 insertions, 4 deletions

diff --git a/sw/CppunitTest_sw_layoutwriter.mk b/sw/CppunitTest_sw_layoutwriter.mk
new file mode 100644
index 000000000000..675299180e44
--- /dev/null
+++ b/sw/CppunitTest_sw_layoutwriter.mk
@@ -0,0 +1,72 @@
+# -*- Mode: makefile-gmake; tab-width: 4; indent-tabs-mode: t -*-
+#*************************************************************************
+#
+# 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/.
+#
+#*************************************************************************
+
+$(eval $(call gb_CppunitTest_CppunitTest,sw_layoutwriter))
+
+$(eval $(call gb_CppunitTest_add_exception_objects,sw_layoutwriter, \
+    sw/qa/extras/layout/layout \
+))
+
+# note: this links msword only for the reason to have a order dependency,
+# because "make sw.check" will not see the dependency through services.rdb
+$(eval $(call gb_CppunitTest_use_libraries,sw_layoutwriter, \
+    comphelper \
+    cppu \
+    cppuhelper \
+    editeng \
+    msword \
+    sal \
+    sfx \
+    svl \
+    svt \
+    svxcore \
+    sw \
+    test \
+    unotest \
+    vcl \
+    tl \
+    utl \
+))
+
+$(eval $(call gb_CppunitTest_use_externals,sw_layoutwriter,\
+    boost_headers \
+    libxml2 \
+))
+
+$(eval $(call gb_CppunitTest_set_include,sw_layoutwriter,\
+    -I$(SRCDIR)/sw/inc \
+    -I$(SRCDIR)/sw/source/core/inc \
+    -I$(SRCDIR)/sw/qa/extras/inc \
+    $$(INCLUDE) \
+))
+
+$(eval $(call gb_CppunitTest_use_sdk_api,sw_layoutwriter))
+
+$(eval $(call gb_CppunitTest_use_ure,sw_layoutwriter))
+$(eval $(call gb_CppunitTest_use_vcl,sw_layoutwriter))
+
+$(eval $(call gb_CppunitTest_use_rdb,sw_layoutwriter,services))
+
+$(eval $(call gb_CppunitTest_use_configuration,sw_layoutwriter))
+
+$(eval $(call gb_CppunitTest_use_uiconfigs,sw_layoutwriter, \
+    modules/swriter \
+))
+
+$(call gb_CppunitTest_get_target,sw_layoutwriter): \
+    $(call gb_Library_get_target,textconv_dict)
+
+ifneq ($(filter MORE_FONTS,$(BUILD_TYPE)),)
+$(call gb_CppunitTest_get_target,sw_layoutwriter): \
+    $(call gb_ExternalPackage_get_target,fonts_liberation)
+endif
+
+# vim: set noet sw=4 ts=4:
diff --git a/sw/Module_sw.mk b/sw/Module_sw.mk
index 39b466fc616f..981c68836ce8 100644
--- a/sw/Module_sw.mk
+++ b/sw/Module_sw.mk
@@ -69,6 +69,7 @@ $(eval $(call gb_Module_add_slowcheck_targets,sw,\
     CppunitTest_sw_odfexport \
     CppunitTest_sw_odfimport \
     CppunitTest_sw_uiwriter \
+    CppunitTest_sw_layoutwriter \
     CppunitTest_sw_mailmerge \
     CppunitTest_sw_globalfilter \
 ))
diff --git a/sw/inc/calc.hxx b/sw/inc/calc.hxx
index 6b85dbdf0968..fd68e0708ced 100644
--- a/sw/inc/calc.hxx
+++ b/sw/inc/calc.hxx
@@ -197,6 +197,7 @@ public:
 
     bool        Push(const SwUserFieldType* pUserFieldType);
     void        Pop();
+    CharClass* GetCharClass();
 
     void        SetCalcError( SwCalcError eErr )    { eError = eErr; }
     bool        IsCalcError() const                 { return 0 != eError; }
diff --git a/sw/inc/usrfld.hxx b/sw/inc/usrfld.hxx
index 8f57b78c4787..c874a9dea769 100644
--- a/sw/inc/usrfld.hxx
+++ b/sw/inc/usrfld.hxx
@@ -26,12 +26,20 @@ class SfxPoolItem;
 class SwCalc;
 class SwDoc;
 
+/**
+ * The shared part of a user field.
+ *
+ * Tracks the value, but conversion between the float and string representation
+ * always happens with the system locale.
+ */
 class SW_DLLPUBLIC SwUserFieldType : public SwValueFieldType
 {
     bool    bValidValue : 1;
     bool    bDeleted : 1;
+    /// Float value type.
     double  nValue;
     OUString  aName;
+    /// String value type.
     OUString  aContent;
     sal_uInt16  nType;
 
@@ -87,6 +95,12 @@ inline void SwUserFieldType::SetType(sal_uInt16 nSub)
     EnableFormat(!(nSub & nsSwGetSetExpType::GSE_STRING));
 }
 
+/**
+ * The non-shared part of a user field.
+ *
+ * Tracks the number format and the language, conversion between the float and
+ * string representation is independent from the system locale.
+ */
 class SW_DLLPUBLIC SwUserField : public SwValueField
 {
     sal_uInt16  nSubType;
diff --git a/sw/qa/extras/layout/data/user-field-type-language.fodt b/sw/qa/extras/layout/data/user-field-type-language.fodt
new file mode 100644
index 000000000000..f741add7ddd7
--- /dev/null
+++ b/sw/qa/extras/layout/data/user-field-type-language.fodt
@@ -0,0 +1,21 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<office:document xmlns:office="urn:oasis:names:tc:opendocument:xmlns:office:1.0" xmlns:style="urn:oasis:names:tc:opendocument:xmlns:style:1.0" xmlns:text="urn:oasis:names:tc:opendocument:xmlns:text:1.0" xmlns:fo="urn:oasis:names:tc:opendocument:xmlns:xsl-fo-compatible:1.0" xmlns:number="urn:oasis:names:tc:opendocument:xmlns:datastyle:1.0" office:version="1.2" office:mimetype="application/vnd.oasis.opendocument.text">
+  <office:styles>
+    <style:default-style style:family="paragraph">
+      <style:text-properties fo:language="en" fo:country="GB"/>
+    </style:default-style>
+  </office:styles>
+  <office:automatic-styles>
+    <number:number-style style:name="N10004" number:language="en" number:country="GB">
+      <number:number number:decimal-places="2" number:min-integer-digits="1" number:grouping="true"/>
+    </number:number-style>
+  </office:automatic-styles>
+  <office:body>
+    <office:text text:use-soft-page-breaks="true">
+      <text:user-field-decls>
+        <text:user-field-decl office:value-type="float" office:value="1234.56" text:name="user-field-decl-name-example"/>
+      </text:user-field-decls>
+      <text:p>Before <text:user-field-get style:data-style-name="N10004" text:name="user-field-decl-name-example">1,234.56</text:user-field-get> after.</text:p>
+    </office:text>
+  </office:body>
+</office:document>
diff --git a/sw/qa/extras/layout/layout.cxx b/sw/qa/extras/layout/layout.cxx
new file mode 100644
index 000000000000..84d1e55e5a22
--- /dev/null
+++ b/sw/qa/extras/layout/layout.cxx
@@ -0,0 +1,63 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * 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/.
+ */
+
+#include <swmodeltestbase.hxx>
+#include <test/mtfxmldump.hxx>
+#include <comphelper/scopeguard.hxx>
+#include <unotools/syslocaleoptions.hxx>
+
+static char const DATA_DIRECTORY[] = "/sw/qa/extras/layout/data/";
+
+/// Test to assert layout / rendering result of Writer.
+class SwLayoutWriter : public SwModelTestBase
+{
+public:
+    void testUserFieldTypeLanguage();
+
+    CPPUNIT_TEST_SUITE(SwLayoutWriter);
+    CPPUNIT_TEST(testUserFieldTypeLanguage);
+    CPPUNIT_TEST_SUITE_END();
+
+private:
+    SwDoc* createDoc(const char* pName = nullptr);
+};
+
+SwDoc* SwLayoutWriter::createDoc(const char* pName)
+{
+    load(DATA_DIRECTORY, pName);
+
+    SwXTextDocument* pTextDoc = dynamic_cast<SwXTextDocument*>(mxComponent.get());
+    CPPUNIT_ASSERT(pTextDoc);
+    return pTextDoc->GetDocShell()->GetDoc();
+}
+
+void SwLayoutWriter::testUserFieldTypeLanguage()
+{
+    // Set the system locale to German, the document will be English.
+    SvtSysLocaleOptions aOptions;
+    aOptions.SetLocaleConfigString("de-DE");
+    aOptions.Commit();
+    comphelper::ScopeGuard g([&aOptions] {
+        aOptions.SetLocaleConfigString(OUString());
+        aOptions.Commit();
+    });
+
+    SwDoc* pDoc = createDoc("user-field-type-language.fodt");
+    SwViewShell* pViewShell = pDoc->getIDocumentLayoutAccess().GetCurrentViewShell();
+    pViewShell->UpdateFields();
+    xmlDocPtr pXmlDoc = parseLayoutDump();
+    // This was "123,456.00", via a buggy 1234.56 -> 1234,56 -> 123456 ->
+    // 123,456.00 transform chain.
+    assertXPath(pXmlDoc, "/root/page/body/txt/Special[@nType='POR_FLD']", "rText", "1,234.56");
+}
+
+CPPUNIT_TEST_SUITE_REGISTRATION(SwLayoutWriter);
+CPPUNIT_PLUGIN_IMPLEMENT();
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
diff --git a/sw/source/core/bastyp/calc.cxx b/sw/source/core/bastyp/calc.cxx
index 272b89f9357f..9f58d3bd5115 100644
--- a/sw/source/core/bastyp/calc.cxx
+++ b/sw/source/core/bastyp/calc.cxx
@@ -633,6 +633,11 @@ void SwCalc::Pop()
     aRekurStack.pop_back();
 }
 
+CharClass* SwCalc::GetCharClass()
+{
+    return pCharClass;
+}
+
 SwCalcOper SwCalc::GetToken()
 {
 #if OSL_DEBUG_LEVEL > 1
diff --git a/sw/source/core/fields/usrfld.cxx b/sw/source/core/fields/usrfld.cxx
index e14ffa13e037..f67f74a81113 100644
--- a/sw/source/core/fields/usrfld.cxx
+++ b/sw/source/core/fields/usrfld.cxx
@@ -35,6 +35,18 @@
 
 using namespace ::com::sun::star;
 
+namespace
+{
+/**
+ * Returns the language used for float <-> string conversions in
+ * SwUserFieldType.
+ */
+LanguageType GetFieldTypeLanguage()
+{
+    return LANGUAGE_SYSTEM;
+}
+}
+
 // Userfields
 
 SwUserField::SwUserField(SwUserFieldType* pTyp, sal_uInt16 nSub, sal_uInt32 nFormat)
@@ -218,7 +230,21 @@ double SwUserFieldType::GetValue( SwCalc& rCalc )
         rCalc.SetCalcError( CALC_SYNTAX );
         return 0;
     }
+
+    // See if we need to temporarily switch rCalc's language: in case it
+    // differs from the field type locale.
+    CharClass* pCharClass = rCalc.GetCharClass();
+    LanguageTag aCalcLanguage = pCharClass->getLanguageTag();
+    LanguageTag aFieldTypeLanguage(GetFieldTypeLanguage());
+    bool bSwitchLanguage = aCalcLanguage != aFieldTypeLanguage;
+    if (bSwitchLanguage)
+        pCharClass->setLanguageTag(aFieldTypeLanguage);
+
     nValue = rCalc.Calculate( aContent ).GetDouble();
+
+    if (bSwitchLanguage)
+        pCharClass->setLanguageTag(aCalcLanguage);
+
     rCalc.Pop();
 
     if( !rCalc.IsCalcError() )
@@ -302,10 +328,7 @@ bool SwUserFieldType::PutValue( const uno::Any& rAny, sal_uInt16 nWhichId )
             rAny >>= fVal;
             nValue = fVal;
 
-            // The following line is in fact wrong, since the language is unknown (is part of the
-            // field) and, thus, aContent should also belong to the field. Each field can have a
-            // different language, but the same content with just different formatting.
-            aContent = DoubleToString(nValue, static_cast<sal_uInt32>(LANGUAGE_SYSTEM));
+            aContent = DoubleToString(nValue, static_cast<sal_uInt16>(GetFieldTypeLanguage()));
         }
         break;
     case FIELD_PROP_PAR2: