Fix race condition in synchronous requests.

Author: max99x

lib/XMLHttpRequest.js

@@ -422,6 +422,7 @@ exports.XMLHttpRequest = function() {
       self.dispatchEvent("loadstart");
     } else { // Synchronous
       // Create a temporary file for communication with the other Node process
+      var contentFile = ".node-xmlhttprequest-content-" + process.pid;
       var syncFile = ".node-xmlhttprequest-sync-" + process.pid;
       fs.writeFileSync(syncFile, "", "utf8");
       // The async request the other Node process executes
@@ -432,28 +433,33 @@ exports.XMLHttpRequest = function() {
         + "var req = doRequest(options, function(response) {"
         + "response.setEncoding('utf8');"
         + "response.on('data', function(chunk) {"
-        + "responseText += chunk;"
+        + "  responseText += chunk;"
         + "});"
         + "response.on('end', function() {"
-        + "fs.writeFileSync('" + syncFile + "', 'NODE-XMLHTTPREQUEST-STATUS:' + response.statusCode + ',' + responseText, 'utf8');"
+        + "fs.writeFileSync('" + contentFile + "', 'NODE-XMLHTTPREQUEST-STATUS:' + response.statusCode + ',' + responseText, 'utf8');"
+        + "fs.unlinkSync('" + syncFile + "');"
         + "});"
         + "response.on('error', function(error) {"
-        + "fs.writeFileSync('" + syncFile + "', 'NODE-XMLHTTPREQUEST-ERROR:' + JSON.stringify(error), 'utf8');"
+        + "fs.writeFileSync('" + contentFile + "', 'NODE-XMLHTTPREQUEST-ERROR:' + JSON.stringify(error), 'utf8');"
+        + "fs.unlinkSync('" + syncFile + "');"
         + "});"
         + "}).on('error', function(error) {"
-        + "fs.writeFileSync('" + syncFile + "', 'NODE-XMLHTTPREQUEST-ERROR:' + JSON.stringify(error), 'utf8');"
+        + "fs.writeFileSync('" + contentFile + "', 'NODE-XMLHTTPREQUEST-ERROR:' + JSON.stringify(error), 'utf8');"
+        + "fs.unlinkSync('" + syncFile + "');"
         + "});"
         + (data ? "req.write('" + data.replace(/'/g, "\\'") + "');":"")
         + "req.end();";
       // Start the other Node Process, executing this string
       syncProc = spawn(process.argv[0], ["-e", execString]);
-      while((self.responseText = fs.readFileSync(syncFile, 'utf8')) == "") {
-        // Wait while the file is empty
+      var statusText;
+      while(fs.existsSync(syncFile)) {
+        // Wait while the sync file is empty
       }
+      self.responseText = fs.readFileSync(contentFile, 'utf8');
       // Kill the child process once the file has data
       syncProc.stdin.end();
       // Remove the temporary file
-      fs.unlinkSync(syncFile);
+      fs.unlinkSync(contentFile);
       if (self.responseText.match(/^NODE-XMLHTTPREQUEST-ERROR:/)) {
         // If the file returned an error, handle it
         var errorObj = self.responseText.replace(/^NODE-XMLHTTPREQUEST-ERROR:/, "");