fix a bug in dispatchmessage

[lcore.git] / lmessages.pas

diff --git a/lmessages.pas b/lmessages.pas
index db26b38f199665470f4edef0c7e31906cba03129..d6e3745b770868fe5746fedb1bfb3f9c2a049437 100755 (executable)
--- a/lmessages.pas
+++ b/lmessages.pas
@@ -1,9 +1,24 @@
+{ Copyright (C) 2005 Bas Steendijk and Peter Green\r
+  For conditions of distribution and use, see copyright notice in zlib_license.txt\r
+  which is included in the package\r
+  ----------------------------------------------------------------------------- }\r
+\r
+//this unit provides a rough approximation of windows messages on linux\r
+//it is usefull for multithreaded applications on linux to communicate back to\r
+//the main lcore thread\r
+//This unit is *nix only, on windows you should use the real thing\r
+\r
 unit lmessages;\r
 //windows messages like system based on lcore tasks\r
 interface\r
 \r
 uses pgtypes,sysutils,bsearchtree,strings,syncobjs;\r
 \r
+\r
+{$if (fpc_version < 2) or ((fpc_version=2) and ((fpc_release < 2) or ((fpc_release = 2) and (fpc_patch < 2)) ))}\r
+  {$error this code is only supported under fpc 2.2.2 and above due to bugs in the eventobject code in older versions}\r
+{$endif}\r
+\r
 type\r
   lparam=taddrint;\r
   wparam=taddrint;\r
@@ -394,11 +409,15 @@ begin
       //we have to get the window procedure while the structurelock\r
       //is still held as the window could be destroyed from another thread\r
       //otherwise.\r
-      windowproc := window.windowproc;\r
+      if window <> nil then begin
+        windowproc := window.windowproc;\r
+      end else begin
+        windowproc := nil;
+      end;
     finally\r
       structurelock.release;\r
     end;\r
-    if window <> nil then begin\r
+    if windowproc <> nil then begin\r
       result := windowproc(lpmsg.hwnd,lpmsg.message,lpmsg.wparam,lpmsg.lparam);\r
     end else begin\r
       result := -1;\r