Resolves: #i94895# fix illegal result of Replace runtime function"

and adjust the basic test-case, which is surely wrong

The syntax for REPLACE is:

// Replace(expression, find, replace[, start[, count[, compare]]])

surely in the case of a start of 3 the preceeding chars should
be returned unchanged in the result, not stripped off as before
this change.

This reverts commit 869402a5.

Change-Id: Ie710e4de9e7e35c84abe2770142a963532820af4

basic/qa/vba_tests/replace.vb

@@ -37,7 +37,7 @@ Function verify_testReplace() as String
     retStr = Replace(srcStr, destStr, repStr, compare:=vbTextCompare)
     TestLog_ASSERT retStr = "aefefdef", "text compare:" & retStr
     retStr = Replace(srcStr, destStr, repStr, 3, -1, vbBinaryCompare)
-    TestLog_ASSERT retStr = "cefdBc", "start = 3:" & retStr
+    TestLog_ASSERT retStr = "abcefdBc", "start = 3:" & retStr
     retStr = Replace(srcStr, destStr, repStr, 1, 2, vbBinaryCompare)
     TestLog_ASSERT retStr = "aefefdBc", "count = 2: " & retStr
     retStr = Replace(srcStr, destStr, repStr, 1, 0, vbBinaryCompare)

basic/source/runtime/methods.cxx

@@ -1405,7 +1405,7 @@ RTLFUNC(Replace)
                 if( nPos >= 0 )
                 {
                     aExpStr = aExpStr.replaceAt( nPos, nFindStrLen, aReplaceStr );
-                    nPos = nPos - nFindStrLen + nReplaceStrLen + 1;
+                    nPos = nPos + nReplaceStrLen;
                     nCounts++;
                 }
                 else
@@ -1414,7 +1414,7 @@ RTLFUNC(Replace)
                 }
             }
         }
-        rPar.Get(0)->PutString( aExpStr.copy( lStartPos - 1 )  );
+        rPar.Get(0)->PutString( aExpStr  );
     }
 }