From 5bbd5fce2f1c0287e0d28b1334f0ccfe216cc969 Mon Sep 17 00:00:00 2001
From: "Admiral H. Curtiss" <pikachu025@gmail.com>
Date: Sat, 19 Dec 2020 17:21:58 +0100
Subject: [PATCH] Common: Write PNGs in two steps to allow Unicode target
 paths.

---
 Source/Core/Common/Image.cpp | 24 +++++++++++++++++++++---
 1 file changed, 21 insertions(+), 3 deletions(-)

diff --git a/Source/Core/Common/Image.cpp b/Source/Core/Common/Image.cpp
index 678a64db8c..478d4b42ab 100644
--- a/Source/Core/Common/Image.cpp
+++ b/Source/Core/Common/Image.cpp
@@ -10,6 +10,7 @@
 #include <png.h>
 
 #include "Common/CommonTypes.h"
+#include "Common/File.h"
 
 namespace Common
 {
@@ -47,22 +48,39 @@ bool SavePNG(const std::string& path, const u8* input, ImageByteFormat format, u
   png.width = width;
   png.height = height;
 
+  size_t byte_per_pixel;
   switch (format)
   {
   case ImageByteFormat::RGB:
     png.format = PNG_FORMAT_RGB;
+    byte_per_pixel = 3;
     break;
   case ImageByteFormat::RGBA:
     png.format = PNG_FORMAT_RGBA;
+    byte_per_pixel = 4;
     break;
   default:
     return false;
   }
 
-  png_image_write_to_file(&png, path.c_str(), 0, input, stride, nullptr);
-  if (png.warning_or_error & PNG_IMAGE_ERROR)
+  // libpng doesn't handle non-ASCII characters in path, so write in two steps:
+  // first to memory, then to file
+  std::vector<u8> buffer(byte_per_pixel * width * height);
+  png_alloc_size_t size = buffer.size();
+  int success = png_image_write_to_memory(&png, buffer.data(), &size, 0, input, stride, nullptr);
+  if (!success && size > buffer.size())
+  {
+    // initial buffer size guess was too small, set to the now-known size and retry
+    buffer.resize(size);
+    png.warning_or_error = 0;
+    success = png_image_write_to_memory(&png, buffer.data(), &size, 0, input, stride, nullptr);
+  }
+  if (!success || (png.warning_or_error & PNG_IMAGE_ERROR) != 0)
     return false;
 
-  return true;
+  File::IOFile outfile(path, "wb");
+  if (!outfile)
+    return false;
+  return outfile.WriteBytes(buffer.data(), size);
 }
 }  // namespace Common