Fix splitting of "permission-for-group/-user:" strings

...that had been introduced in f5c266695a4a88da7db971a21915e2bbf758d48e
"tdf#66398 Parse and output permissions for DOCX using bookmarks":

For one, in DocxAttributeOutput::DoWritePermissionTagStart permissionIdAndName
was left empty in the permission-for-user case.  This had already been addressed
for DocxAttributeOutput::DoWritePermissionTagEnd in
7f0b7410e84a222d8fbee7c4fadd3b40028a068d "permissionIdAndName is empty in
permission-for-user case".  But from the calling code it looks like in both
functions that permission will always start with either "permission-for-group:"
or "permission-for-user:", so assert that rather than silently doing nothing if
the assumption is wrong.

For another, in both functions the code didn't take any precaution if
permissionIdAndName didn't contain a colon (which would cause undefined behavior
when OUString::copy is called with a negative count argument).  Again, from the
calling code assume that permissionIdAndName will always contain a colon, and
assert that.

Change-Id: Ia7432413c138d47efbe8aec76f14c561ac241fb3
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/122387
Tested-by: Jenkins
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>

1 files changed, 14 insertions, 9 deletions

diff --git a/sw/source/filter/ww8/docxattributeoutput.cxx b/sw/source/filter/ww8/docxattributeoutput.cxx
index c2aa3880ece0..5da71ff6f820 100644
--- a/sw/source/filter/ww8/docxattributeoutput.cxx
+++ b/sw/source/filter/ww8/docxattributeoutput.cxx
@@ -1794,6 +1794,7 @@ void DocxAttributeOutput::DoWritePermissionTagStart(const OUString & permission)
     if (permission.startsWith("permission-for-group:", &permissionIdAndName))
     {
         const sal_Int32 sparatorIndex = permissionIdAndName.indexOf(':');
+        assert(sparatorIndex != -1);
         const OUString permissionId   = permissionIdAndName.copy(0, sparatorIndex);
         const OUString permissionName = permissionIdAndName.copy(sparatorIndex + 1);
 
@@ -1801,9 +1802,12 @@ void DocxAttributeOutput::DoWritePermissionTagStart(const OUString & permission)
             FSNS(XML_w, XML_id), BookmarkToWord(permissionId),
             FSNS(XML_w, XML_edGrp), BookmarkToWord(permissionName));
     }
-    else // if (permission.startsWith("permission-for-user:", &permissionIdAndName))
+    else
     {
+        auto const ok = permission.startsWith("permission-for-user:", &permissionIdAndName);
+        assert(ok); (void)ok;
         const sal_Int32 sparatorIndex = permissionIdAndName.indexOf(':');
+        assert(sparatorIndex != -1);
         const OUString permissionId   = permissionIdAndName.copy(0, sparatorIndex);
         const OUString permissionName = permissionIdAndName.copy(sparatorIndex + 1);
 
@@ -1825,15 +1829,16 @@ void DocxAttributeOutput::DoWritePermissionTagEnd(const OUString & permission)
 {
     OUString permissionIdAndName;
 
-    if (permission.startsWith("permission-for-group:", &permissionIdAndName) ||
-        permission.startsWith("permission-for-user:", &permissionIdAndName))
-    {
-        const sal_Int32 sparatorIndex = permissionIdAndName.indexOf(':');
-        const OUString permissionId   = permissionIdAndName.copy(0, sparatorIndex);
+    auto const ok = permission.startsWith("permission-for-group:", &permissionIdAndName) ||
+        permission.startsWith("permission-for-user:", &permissionIdAndName);
+    assert(ok); (void)ok;
 
-        m_pSerializer->singleElementNS(XML_w, XML_permEnd,
-            FSNS(XML_w, XML_id), BookmarkToWord(permissionId));
-    }
+    const sal_Int32 sparatorIndex = permissionIdAndName.indexOf(':');
+    assert(sparatorIndex != -1);
+    const OUString permissionId   = permissionIdAndName.copy(0, sparatorIndex);
+
+    m_pSerializer->singleElementNS(XML_w, XML_permEnd,
+        FSNS(XML_w, XML_id), BookmarkToWord(permissionId));
 }
 
 /// Write the start permissions