work around crash when starting a download if download folder not specified in IC preferences (e.g. a fresh user account) b=265903 sr=pinkerton

xpcom/io/nsDirectoryService.cpp

@@ -889,13 +889,31 @@ nsDirectoryService::GetFile(const char *prop, PRBool *persistent, nsIFile **_ret
             err = ::ICStart(&icInstance, 'XPCM');
             if (err == noErr)
             {
-                ICAttr attrs;
-                ICFileSpec icFileSpec;
-                long size = kICFileSpecHeaderSize;
-                err = ::ICGetPref(icInstance, kICDownloadFolder, &attrs, &icFileSpec, &size);
-                if (err == noErr || (err == icTruncatedErr && size >= kICFileSpecHeaderSize))
+                // ICGetPref() crashes when getting the download directory if the download
+                // directory has never been specified (e.g. a new user account), bug 265903.
+                // To work around this we enumerate through the IC prefs to see if the
+                // download directory has been specified before trying to obtain it.
+                long numPrefs = 0;
+                err = ::ICCountPref(icInstance, &numPrefs);
+                if (err == noErr)
                 {
-                    rv = localMacFile->InitWithFSSpec(&icFileSpec.fss);
+                    for ( long i = 0; i < numPrefs; ++i )
+                    {
+                        Str255 key;
+                        err = ::ICGetIndPref(icInstance, i, key);
+                        if ( err == noErr && ( PLstrcmp( key, kICDownloadFolder ) == 0 ) )
+                        {
+                            ICAttr attrs;
+                            ICFileSpec icFileSpec;
+            	            long size = kICFileSpecHeaderSize;
+                            err = ::ICGetPref(icInstance, kICDownloadFolder, &attrs, &icFileSpec, &size);
+                            if (err == noErr || (err == icTruncatedErr && size >= kICFileSpecHeaderSize))
+                            {
+                                rv = localMacFile->InitWithFSSpec(&icFileSpec.fss);
+                            }
+                            break;
+                        }
+                    }
                 }
                 ::ICStop(icInstance);
             }