Better error messages.

dlls/user/msg16.c

@@ -102,7 +102,7 @@ BOOL16 WINAPI PostMessage16( HWND16 hwnd16, UINT16 msg, WPARAM16 wparam, LPARAM
     case 0:
         return PostMessageW( hwnd, msg32, wparam32, lparam );
     case 1:
-        ERR( "16-bit message %x contains pointer, cannot post\n", msg );
+        ERR( "16-bit message 0x%04x contains pointer, cannot post\n", msg );
         return FALSE;
     default:
         return FALSE;

dlls/winspool/info.c

@@ -160,7 +160,7 @@ CUPS_LoadPrinters(void) {
 
 	if (!AddPrinterA(NULL,2,(LPBYTE)&pinfo2a)) {
 	    if (GetLastError()!=ERROR_PRINTER_ALREADY_EXISTS)
-	        ERR("%s not added by AddPrinterA (%ld)\n",printers[i],GetLastError());
+	        ERR("printer '%s' not added by AddPrinterA (error %ld)\n",printers[i],GetLastError());
 	}
 	HeapFree(GetProcessHeap(),0,port);
     }
@@ -1060,7 +1060,7 @@ HANDLE WINAPI AddPrinterW(LPWSTR pName, DWORD Level, LPBYTE pPrinter)
      */
     size = DocumentPropertiesW(0, -1, pi->pPrinterName, NULL, NULL, 0);
     if(size < 0) {
-        FIXME("DocumentProperties fails\n");
+        FIXME("DocumentPropertiesW on printer '%s' fails\n", pi->pPrinterName);
 	size = sizeof(DEVMODEW);
     }
     if(pi->pDevMode)
@@ -1069,7 +1069,7 @@ HANDLE WINAPI AddPrinterW(LPWSTR pName, DWORD Level, LPBYTE pPrinter)
 	dmW = HeapAlloc(GetProcessHeap(), 0, size);
 	dmW->dmSize = size;
 	if (0>DocumentPropertiesW(0,-1,pi->pPrinterName,dmW,NULL,DM_OUT_BUFFER)) {
-	    ERR("DocumentPropertiesW failed!\n");
+	    ERR("DocumentPropertiesW on printer '%s' failed!\n", pi->pPrinterName);
 	    SetLastError(ERROR_UNKNOWN_PRINTER_DRIVER);
 	    return 0;
 	}