Bug 392867 - libpng requires error callbacks to not return. Separate out nsPNGDecoder's ErrorCallback and WarningCallback, and call longjmp from ErrorCallback. r=joe a=ehsan

image/encoders/png/nsPNGEncoder.cpp

@@ -147,7 +147,7 @@ NS_IMETHODIMP nsPNGEncoder::StartImageEncode(PRUint32 aWidth,
   mPNG = png_create_write_struct(PNG_LIBPNG_VER_STRING,
                                  nsnull,
                                  ErrorCallback,
-                                 ErrorCallback);
+                                 WarningCallback);
   if (! mPNG)
     return NS_ERROR_OUT_OF_MEMORY;
 
@@ -665,10 +665,10 @@ nsPNGEncoder::StripAlpha(const PRUint8* aSrc, PRUint8* aDest,
 }
 
 
-// nsPNGEncoder::ErrorCallback
+// nsPNGEncoder::WarningCallback
 
 void // static
-nsPNGEncoder::ErrorCallback(png_structp png_ptr,
+nsPNGEncoder::WarningCallback(png_structp png_ptr,
                             png_const_charp warning_msg)
 {
 #ifdef DEBUG
@@ -679,6 +679,25 @@ nsPNGEncoder::ErrorCallback(png_structp png_ptr,
 }
 
 
+// nsPNGEncoder::ErrorCallback
+
+void // static
+nsPNGEncoder::ErrorCallback(png_structp png_ptr,
+                            png_const_charp error_msg)
+{
+#ifdef DEBUG
+	// XXX: these messages are probably useful callers...
+        // use nsIConsoleService?
+	PR_fprintf(PR_STDERR, "PNG Encoder: %s\n", error_msg);;
+#endif
+#if PNG_LIBPNG_VER < 10500
+        longjmp(png_ptr->jmpbuf, 1);
+#else
+        png_longjmp(png_ptr, 1);
+#endif
+}
+
+
 // nsPNGEncoder::WriteCallback
 
 void // static

image/encoders/png/nsPNGEncoder.h

@@ -81,7 +81,8 @@ protected:
                           PRUint32 aPixelWidth, bool aUseTransparency);
   void StripAlpha(const PRUint8* aSrc, PRUint8* aDest,
                   PRUint32 aPixelWidth);
-  static void ErrorCallback(png_structp png_ptr, png_const_charp warning_msg);
+  static void WarningCallback(png_structp png_ptr, png_const_charp warning_msg);
+  static void ErrorCallback(png_structp png_ptr, png_const_charp error_msg);
   static void WriteCallback(png_structp png, png_bytep data, png_size_t size);
   void NotifyListener();