From 04b8b4b08f7ac70d39e8edda4f90a44e8f5bb454 Mon Sep 17 00:00:00 2001
From: "Adam D. Ruppe" <destructionator@gmail.com>
Date: Thu, 1 Mar 2018 11:30:25 -0500
Subject: [PATCH] ketmar memory management patch to handle deprecated delete

---
 color.d    | 25 +++++++++++++++++++++++++
 nanovega.d | 11 +++++------
 2 files changed, 30 insertions(+), 6 deletions(-)

diff --git a/color.d b/color.d
index 1396f88..c9814f6 100644
--- a/color.d
+++ b/color.d
@@ -837,6 +837,16 @@ interface MemoryImage {
 		}
 	}
 
+	// ***This method is deliberately not publicly documented.***
+	// What it does is unconditionally frees internal image storage, without any sanity checks.
+	// If you will do this, make sure that you have no references to image data left (like
+	// slices of [data] array, for example). Those references will become invalid, and WILL
+	// lead to Undefined Behavior.
+	// tl;dr: IF YOU HAVE *ANY* QUESTIONS REGARDING THIS COMMENT, DON'T USE THIS!
+	// Note to implementors: it is safe to simply do nothing in this method.
+	// Also, it should be safe to call this method twice or more.
+	void clearInternal () nothrow @system @nogc;
+
 	/// Convenient alias for `fromImage`
 	alias fromImageFile = fromImage;
 }
@@ -850,6 +860,14 @@ class IndexedImage : MemoryImage {
 	/// the data as indexes into the palette. Stored left to right, top to bottom, no padding.
 	ubyte[] data;
 
+	override void clearInternal () nothrow @system @nogc {
+		import core.memory : GC;
+		// it is safe to call [GC.free] with `null` pointer.
+		GC.free(palette.ptr); palette = null;
+		GC.free(data.ptr); data = null;
+		_width = _height = 0;
+	}
+
 	/// .
 	override int width() const {
 		return _width;
@@ -988,6 +1006,13 @@ class TrueColorImage : MemoryImage {
 	int _width;
 	int _height;
 
+	override void clearInternal () nothrow @system @nogc {
+		import core.memory : GC;
+		// it is safe to call [GC.free] with `null` pointer.
+		GC.free(imageData.bytes.ptr); imageData.bytes = null;
+		_width = _height = 0;
+	}
+
 	/// .
 	override TrueColorImage clone() const {
 		auto n = new TrueColorImage(width, height);
diff --git a/nanovega.d b/nanovega.d
index 2a87b68..512e9b9 100644
--- a/nanovega.d
+++ b/nanovega.d
@@ -2968,20 +2968,19 @@ public NVGImage createImage() (NVGContext ctx, const(char)[] filename, const(NVG
   static if (NanoVegaHasArsdImage) {
     import arsd.image;
     // do we have new arsd API to load images?
-    static if (!is(typeof(MemoryImage.fromImageFile))) {
+    static if (!is(typeof(MemoryImage.fromImageFile)) || !is(typeof(MemoryImage.clearInternal))) {
       static assert(0, "Sorry, your ARSD is too old. Please, update it.");
     }
     try {
       auto oimg = MemoryImage.fromImageFile(filename);
       if (auto img = cast(TrueColorImage)oimg) {
-        oimg = null;
-        scope(exit) { delete img.imageData.bytes; delete img; }
+        scope(exit) oimg.clearInternal();
         return ctx.createImageRGBA(img.width, img.height, img.imageData.bytes[], imageFlagsList);
       } else {
         TrueColorImage img = oimg.getAsTrueColorImage;
-        if (auto xi = cast(IndexedImage)oimg) { delete xi.palette; delete xi.data; delete xi; }
+        scope(exit) img.clearInternal();
+        oimg.clearInternal(); // drop original image, as `getAsTrueColorImage()` MUST create a new one here
         oimg = null;
-        scope(exit) { delete img.imageData.bytes; delete img; }
         return ctx.createImageRGBA(img.width, img.height, img.imageData.bytes[], imageFlagsList);
       }
     } catch (Exception) {}
@@ -3013,7 +3012,7 @@ static if (NanoVegaHasArsdImage) {
       return ctx.createImageRGBA(tc.width, tc.height, tc.imageData.bytes[], imageFlagsList);
     } else {
       auto tc = img.getAsTrueColorImage;
-      scope(exit) { delete tc.imageData.bytes; delete tc; }
+      scope(exit) tc.clearInternal(); // here, it is guaranteed that `tc` is newly allocated image, so it is safe to kill it
       return ctx.createImageRGBA(tc.width, tc.height, tc.imageData.bytes[], imageFlagsList);
     }
   }