HeapAlloc for WSTR must allocate len* sizeof(WCHARS).

dlls/hhctrl.ocx/hhctrl.c

@@ -47,7 +47,7 @@ HWND WINAPI HtmlHelpA(HWND caller, LPCSTR filename, UINT command, DWORD data)
     DWORD len = MultiByteToWideChar( CP_ACP, 0, filename, -1, NULL, 0 );
     HWND result;
 
-    wfile = HeapAlloc( GetProcessHeap(), 0, len );
+    wfile = HeapAlloc( GetProcessHeap(), 0, len  * sizeof(WCHAR));
     MultiByteToWideChar( CP_ACP, 0, filename, -1, wfile, len );
 
     result = HtmlHelpW( caller, wfile, command, data );

dlls/imm32/imm.c

@@ -1265,14 +1265,14 @@ BOOL WINAPI ImmSetCompositionStringA(
     comp_len = MultiByteToWideChar(CP_ACP, 0, lpComp, dwCompLen, NULL, 0);
     if (comp_len)
     {
-        CompBuffer = (WCHAR*)HeapAlloc(GetProcessHeap(),0,comp_len);
+        CompBuffer = (WCHAR*)HeapAlloc(GetProcessHeap(),0,comp_len * sizeof(WCHAR));
         MultiByteToWideChar(CP_ACP, 0, lpComp, dwCompLen, CompBuffer, comp_len);
     }
 
     read_len = MultiByteToWideChar(CP_ACP, 0, lpRead, dwReadLen, NULL, 0);
     if (read_len)
     {
-        ReadBuffer = (WCHAR*)HeapAlloc(GetProcessHeap(),0,read_len);
+        ReadBuffer = (WCHAR*)HeapAlloc(GetProcessHeap(),0,read_len * sizeof(WCHAR));
         MultiByteToWideChar(CP_ACP, 0, lpRead, dwReadLen, ReadBuffer, read_len);
     }
 

dlls/mpr/wnet.c

@@ -1540,7 +1540,7 @@ DWORD WINAPI WNetGetConnectionA( LPCSTR lpLocalName,
 
         if (len)
         {
-            PWSTR wideLocalName = (PWSTR)HeapAlloc(GetProcessHeap(), 0, len);
+            PWSTR wideLocalName = (PWSTR)HeapAlloc(GetProcessHeap(), 0, len * sizeof(WCHAR));
 
             if (wideLocalName)
             {