Fix fast concat of empty strings

Change-Id: Ice9c6974f44be3bc4c9b3533de2a9beb5b146ca5

2 files changed, 11 insertions, 5 deletions

diff --git a/sal/inc/rtl/string.hxx b/sal/inc/rtl/string.hxx
index 2c7a43dba897..aeb752890d1f 100644
--- a/sal/inc/rtl/string.hxx
+++ b/sal/inc/rtl/string.hxx
@@ -262,8 +262,11 @@ public:
         const int l = c.length();
         rtl_String* buffer = NULL;
         rtl_string_new_WithLength( &buffer, l );
-        char* end = c.addData( buffer->buffer );
-        buffer->length = end - buffer->buffer;
+        if (l != 0)
+        {
+            char* end = c.addData( buffer->buffer );
+            buffer->length = end - buffer->buffer;
+        }
         pData = buffer;
     }
 #endif
diff --git a/sal/inc/rtl/ustring.hxx b/sal/inc/rtl/ustring.hxx
index 534bd889f05a..ec9f90ecd46f 100644
--- a/sal/inc/rtl/ustring.hxx
+++ b/sal/inc/rtl/ustring.hxx
@@ -330,9 +330,12 @@ public:
         const int l = c.length();
         rtl_uString* buffer = NULL;
         rtl_uString_new_WithLength( &buffer, l ); // TODO this clears, not necessary
-        sal_Unicode* end = c.addData( buffer->buffer );
-        buffer->length = end - buffer->buffer;
-        // TODO realloc in case buffer->length is noticeably smaller than l ?
+        if (l != 0)
+        {
+            sal_Unicode* end = c.addData( buffer->buffer );
+            buffer->length = end - buffer->buffer;
+            // TODO realloc in case buffer->length is noticeably smaller than l?
+        }
         pData = buffer;
     }
 #endif