tdf#139840 - Use utl::TextSearch to implement the InStr function

In addtion, fixed a crash if the start position is greater than the
length of the string being searched.

Change-Id: I9bcda1131324bdfac6957018e91b3a36dd2dc3d6
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/118996
Tested-by: Jenkins
Reviewed-by: Andreas Heinisch <andreas.heinisch@yahoo.de>

3 files changed, 34 insertions, 15 deletions

diff --git a/basic/qa/basic_coverage/test_instr_method.bas b/basic/qa/basic_coverage/test_instr_method.bas
index ff763cb4226c..9e4545bb3b44 100644
--- a/basic/qa/basic_coverage/test_instr_method.bas
+++ b/basic/qa/basic_coverage/test_instr_method.bas
@@ -18,6 +18,12 @@ Function doUnitTest as String
 
     ' tdf#139840 - case-insensitive operation for non-ASCII characters
     If (InStr(1, "α", "Α", 1) <> 1) Then Exit Function
+    ' tdf#139840 - German Eszett is uppercased to a two-character 'SS'.
+    ' This test should fail after tdf#110003 has been fixed.
+    If (InStr(2, "Straße", "s", 1) <> 5) Then Exit Function
+
+    ' Start position is greater than the length of the string being searched.
+    If (InStr(2, "α", "Α", 1) <> 0) Then Exit Function
 
     doUnitTest = "OK"
 
diff --git a/basic/qa/vba_tests/instr.vb b/basic/qa/vba_tests/instr.vb
index 3ced2a07c8ca..cda19712b296 100644
--- a/basic/qa/vba_tests/instr.vb
+++ b/basic/qa/vba_tests/instr.vb
@@ -32,6 +32,12 @@ Sub verify_testInStr()
 
     ' tdf#139840 - case-insensitive operation for non-ASCII characters
     TestUtil.AssertEqual(InStr(1, "α", "Α", 1), 1, "InStr(1, ""α"", ""Α"", 1)")
+    ' tdf#139840 - German Eszett is uppercased to a two-character 'SS'.
+    ' This test should fail after tdf#110003 has been fixed.
+    TestUtil.AssertEqual(InStr(2, "Straße", "s", 1), 5, "InStr(2, ""Straße"", ""s"", 1)")
+
+    ' Start position is greater than the length of the string being searched.
+    TestUtil.AssertEqual(InStr(2, "α", "Α", 1), 0, "InStr(2, ""α"", ""Α"", 1)")
 
     Exit Sub
 errorHandler:
diff --git a/basic/source/runtime/methods.cxx b/basic/source/runtime/methods.cxx
index e745fa2fd1c6..1055aab142d2 100644
--- a/basic/source/runtime/methods.cxx
+++ b/basic/source/runtime/methods.cxx
@@ -885,25 +885,32 @@ void SbRtl_InStr(StarBASIC *, SbxArray & rPar, bool)
         }
         else
         {
-            if( !bTextMode )
+            const OUString& rStr1 = rPar.Get(nFirstStringPos)->GetOUString();
+            const sal_Int32 nrStr1Len = rStr1.getLength();
+            if (nStartPos > nrStr1Len)
             {
-                const OUString& rStr1 = rPar.Get(nFirstStringPos)->GetOUString();
-                nPos = rStr1.indexOf( rToken, nStartPos - 1 ) + 1;
+                // Start position is greater than the string being searched
+                nPos = 0;
             }
             else
             {
-                OUString aStr1 = rPar.Get(nFirstStringPos)->GetOUString();
-                OUString aToken = rToken;
-
-                // tdf#139840 - case-insensitive operation for non-ASCII characters
-                const css::lang::Locale& rLocale
-                    = Application::GetSettings().GetLanguageTag().getLocale();
-                css::uno::Reference<i18n::XCharacterClassification> xCharClass
-                    = vcl::unohelper::CreateCharacterClassification();
-                aStr1 = xCharClass->toUpper(aStr1, 0, aStr1.getLength(), rLocale);
-                aToken = xCharClass->toUpper(aToken, 0, aToken.getLength(), rLocale);
-
-                nPos = aStr1.indexOf( aToken, nStartPos-1 ) + 1;
+                if( !bTextMode )
+                {
+                    nPos = rStr1.indexOf( rToken, nStartPos - 1 ) + 1;
+                }
+                else
+                {
+                    // tdf#139840 - case-insensitive operation for non-ASCII characters
+                    i18nutil::SearchOptions2 aSearchOptions;
+                    aSearchOptions.searchString = rToken;
+                    aSearchOptions.AlgorithmType2 = util::SearchAlgorithms2::ABSOLUTE;
+                    aSearchOptions.transliterateFlags |= TransliterationFlags::IGNORE_CASE;
+                    utl::TextSearch textSearch(aSearchOptions);
+
+                    sal_Int32 nStart = nStartPos - 1;
+                    sal_Int32 nEnd = nrStr1Len;
+                    nPos = textSearch.SearchForward(rStr1, &nStart, &nEnd) ? nStart + 1 : 0;
+                }
             }
         }
         rPar.Get(0)->PutLong(nPos);