Bug 1078640: Sanitize path used to load XPCOM on OSX. r=smichaud

xpcom/build/BinaryPath.h

@@ -56,13 +56,29 @@ private:
       return NS_ERROR_FAILURE;
     }
 
+    UInt8 tempBuffer[MAXPATHLEN];
     nsresult rv;
-    if (CFURLGetFileSystemRepresentation(executableURL, false, (UInt8*)aResult,
+    if (CFURLGetFileSystemRepresentation(executableURL, false, tempBuffer,
                                          MAXPATHLEN)) {
       rv = NS_OK;
     } else {
       rv = NS_ERROR_FAILURE;
     }
+
+    // Sanitize path in case the app was launched from Terminal via './firefox'
+    // for example.
+    size_t readPos = 0;
+    size_t writePos = 0;
+    while (tempBuffer[readPos] != '\0') {
+      if (tempBuffer[readPos] == '.' && tempBuffer[readPos + 1] == '/') {
+        readPos += 2;
+      }
+      aResult[writePos] = tempBuffer[readPos];
+      readPos++;
+      writePos++;
+    }
+    aResult[writePos] = '\0';
+
     CFRelease(executableURL);
     return rv;
   }