* fixed fpc_AnsiStr_Concat_multi + test

git-svn-id: trunk@4790 -

.gitattributes

@@ -5832,6 +5832,7 @@ tests/tbs/tb0499.pp svneol=native#text/plain
 tests/tbs/tb0500.pp svneol=native#text/plain
 tests/tbs/tb0501.pp svneol=native#text/plain
 tests/tbs/tb0502.pp svneol=native#text/plain
+tests/tbs/tb0503.pp svneol=native#text/plain
 tests/tbs/ub0060.pp svneol=native#text/plain
 tests/tbs/ub0069.pp svneol=native#text/plain
 tests/tbs/ub0119.pp svneol=native#text/plain

rtl/inc/astrings.inc

@@ -245,6 +245,7 @@ Var
   p,pc        : pointer;
   Size,NewLen,
   OldDestLen  : SizeInt;
+  destcopy    : ansistring;
 begin
   if high(sarr)=0 then
     begin
@@ -253,17 +254,19 @@ begin
     end;
   lowstart:=low(sarr);
   if Pointer(DestS)=Pointer(sarr[lowstart]) then
+    inc(lowstart);
+  { Check for another reuse, then we can't use
+    the append optimization }
+  for i:=lowstart to high(sarr) do
     begin
-      inc(lowstart);
-      { Check for another reuse, then we can't use
-        the append optimization }
-      for i:=lowstart to high(sarr) do
+      if Pointer(DestS)=Pointer(sarr[i]) then
         begin
-          if Pointer(DestS)=Pointer(sarr[i]) then
-            begin
-              lowstart:=low(sarr);
-              break;
-            end;
+          { if DestS is used somewhere in the middle of the expression,
+            we need to make sure the original string still exists after
+            we empty/modify DestS                                       }
+          destcopy:=dests;
+          lowstart:=low(sarr);
+          break;
         end;
     end;
   { Start with empty DestS if we start with concatting

tests/tbs/tb0503.pp

@@ -0,0 +1,41 @@
+procedure testansi;
+var
+  s, q: ansistring;
+begin
+  s := 'hell';
+  s := s+'o';
+  q := '"';
+  q := q+'''';
+  s := s + q + s + 'abc';
+  if (s <> 'hello"''helloabc') then
+    halt(1);
+  s := 'hell';
+  s := s+'o';
+  s := q+s+q;
+  if (s <> '"''hello"''') then
+    halt(2);
+end;
+
+
+procedure testshort;
+var
+  s, q: shortstring;
+begin
+  s := 'hell';
+  s := s+'o';
+  q := '"';
+  q := q+'''';
+  s := s + q + s + 'abc';
+  if (s <> 'hello"''helloabc') then
+    halt(3);
+  s := 'hell';
+  s := s+'o';
+  s := q+s+q;
+  if (s <> '"''hello"''') then
+    halt(4);
+end;
+
+begin
+  testansi;
+  testshort;
+end.