DDEML fix

[Eric Pouech <eric.pouech@wanadoo.fr>]

this patch prevent some crashes in 16 bit DDEML

A+
Name:          dde16
ChangeLog:     fixed some NULL pointer handling errors
License:       X11
GenDate:       2002/10/06 19:21:02 UTC
ModifiedFiles: dlls/user/dde/ddeml16.c
AddedFiles:    
===================================================================
RCS file: /home/cvs/cvsroot/wine/wine/dlls/user/dde/ddeml16.c,v
retrieving revision 1.7
diff -u -u -r1.7 ddeml16.c
--- dlls/user/dde/ddeml16.c	31 May 2002 23:40:54 -0000	1.7
+++ dlls/user/dde/ddeml16.c	18 Aug 2002 20:10:51 -0000
@@ -101,7 +101,7 @@
                                       HCONV hConv, HSZ hsz1, HSZ hsz2,
                                       HDDEDATA hdata, DWORD dwData1, DWORD dwData2)
 {
-    DWORD               d1;
+    DWORD               d1 = 0;
     HDDEDATA            ret;
     CONVCONTEXT16       cc16;
 
@@ -109,8 +109,12 @@
     {
     case XTYP_CONNECT:
     case XTYP_WILDCONNECT:
-        map3216_conv_context(&cc16, (const CONVCONTEXT*)dwData1);
-        d1 = MapLS(&cc16);
+        if (dwData1)
+        {
+            map3216_conv_context(&cc16, (const CONVCONTEXT*)dwData1);
+            d1 = MapLS(&cc16);
+        }
+        else
         break;
     default:
         d1 = dwData1;
@@ -122,7 +126,7 @@
     {
     case XTYP_CONNECT:
     case XTYP_WILDCONNECT:
-        UnMapLS(d1);
+        if (d1 != 0) UnMapLS(d1);
         break;
     }
     return ret;