[tdbf-cvs] SF.net SVN: tdbf:[867] trunk/src/dbf_prscore.pas

[<tw...@us...>]

Revision: 867
          http://sourceforge.net/p/tdbf/code/867
Author:   twm
Date:     2026-03-07 18:25:39 +0000 (Sat, 07 Mar 2026)
Log Message:
-----------
Fix FuncLeftString crash on negative count argument

Clamp count to [0, srcLen] to match dBASE semantics. A negative count
was passed unchecked to Append/Move, causing undefined behavior.
Also removed the redundant always-zero index variable.

Modified Paths:
--------------
    trunk/src/dbf_prscore.pas

Modified: trunk/src/dbf_prscore.pas
===================================================================
--- trunk/src/dbf_prscore.pas	2026-03-07 18:17:23 UTC (rev 866)
+++ trunk/src/dbf_prscore.pas	2026-03-07 18:25:39 UTC (rev 867)
@@ -1666,14 +1666,15 @@
 
 procedure FuncLeftString(Param: PExpressionRec);
 var
-  srcLen, index, count: Integer;
+  srcLen, count: Integer;
 begin
   srcLen := dbfStrLen(Param^.Args[0]);
-  index := 0;
   count := PInteger(Param^.Args[1])^;
-  if index + count > srcLen then
-    count := srcLen - index;
-  Param^.Res.Append(Param^.Args[0]+index, count)
+  if count < 0 then
+    count := 0;
+  if count > srcLen then
+    count := srcLen;
+  Param^.Res.Append(Param^.Args[0], count)
 end;
 
 procedure FuncUppercase(Param: PExpressionRec);

This was sent by the SourceForge.net collaborative development platform, the world's largest Open Source development site.