i#121482# fix backwards regexp search for matches overlapping search start

(cherry picked from commit 854f4ad6)

Additionally fixed unit test, searching backward shall not produce a
different result from searching forward. (erAck)

Change-Id: I952509276875441005e6a4036e6c3089be627dd9

i18npool/qa/cppunit/test_textsearch.cxx

@@ -101,7 +101,7 @@ void TestTextSearch::testSearches()
     sal_Int32 startPos = 2, endPos = 20 ;
     OUString searchStr( "(ab)*a(c|d)+" );
     sal_Int32 fStartRes = 10, fEndRes = 18 ;
-    sal_Int32 bStartRes = 18, bEndRes = 14 ;
+    sal_Int32 bStartRes = 18, bEndRes = 10 ;
 
     // set options
     util::SearchOptions aOptions;

i18npool/source/search/textsearch.cxx

@@ -774,9 +774,15 @@ SearchResult TextSearch::RESrchBkwrd( const OUString& searchStr,
 
     // find the last match
     int nLastPos = 0;
+    int nFoundEnd = 0;
     do {
         nLastPos = pRegexMatcher->start( nIcuErr);
-    } while( pRegexMatcher->find( nLastPos + 1, nIcuErr));
+        nFoundEnd = pRegexMatcher->end( nIcuErr);
+        if( nFoundEnd >= startPos)
+            break;
+        if( nFoundEnd == nLastPos)
+            ++nFoundEnd;
+    } while( pRegexMatcher->find( nFoundEnd, nIcuErr));
 
     // find last match again to get its details
     pRegexMatcher->find( nLastPos, nIcuErr);