rem:  if (!this.exists()) { jslibError(null, "(file doesn't exist)", "NS_ERROR_FAILURE", JS_FILESYSTEM_FILE+":isDir"); return false; } return this.mFileInst.isExecutable(); 
add: var rv = false; try { rv = this.mFileInst.isExecutable(); } catch (e) { rv = false; }  return rv; 
context: isExec : function(){  if (!this.exists()) {    jslibError(null,       "(file doesn't exist)",       "NS_ERROR_FAILURE",       JS_FILESYSTEM_FILE+":isDir");    return false;  }  return this.mFileInst.isExecutable();},
meta: 8395	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/8395/ad31f8ed11639845cff55b2a989a1a6243a89a9b/filesystem.js/buggy/calendar/resources/content/jslib/io/filesystem.js