From c1c9f3b7fe54c5cb614bf9bf153660246aec2f3b Mon Sep 17 00:00:00 2001
From: Ozkan Sezer <sezeroz@gmail.com>
Date: Mon, 27 Jun 2022 14:04:20 +0300
Subject: [PATCH] stb_image_write.h: applied mainstream PR/1337 patch

fixes potential invalid memory access
https://github.com/nothings/stb/pull/1337
---
 Linux/sgml/Quakespasm.sgml | 1 +
 Quake/stb_image_write.h    | 2 +-
 Quakespasm.html            | 6 +++---
 Quakespasm.txt             | 2 ++
 4 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/Linux/sgml/Quakespasm.sgml b/Linux/sgml/Quakespasm.sgml
index ddf3d576..28871c0e 100644
--- a/Linux/sgml/Quakespasm.sgml
+++ b/Linux/sgml/Quakespasm.sgml
@@ -139,6 +139,7 @@ QuakeSpasm 0.94.0 has initial support for playing the 2021 re-release content: C
 <sect1> Changes in 0.94.6<p>
 <itemize>
 <item> Server protocol size check fixes for sounds and particles.
+<item> An invalid memory access fix in the jpg screenshot writer.
 <item> Backported a few fixes to the bundled SDL2-2.0.22 version.
 <item> Minor build fix for C++ compilers.
 </itemize>
diff --git a/Quake/stb_image_write.h b/Quake/stb_image_write.h
index d5904438..260b0b42 100644
--- a/Quake/stb_image_write.h
+++ b/Quake/stb_image_write.h
@@ -381,7 +381,7 @@ static int stbiw__jpg_processDU(stbi__write_context *s, int *bitBuf, int *bitCnt
       int startpos = i;
       int nrzeroes;
       unsigned short bits[2];
-      for (; DU[i]==0 && i<=end0pos; ++i) {
+      for (; i<=end0pos && DU[i]==0; ++i) {
       }
       nrzeroes = i-startpos;
       if ( nrzeroes >= 16 ) {
diff --git a/Quakespasm.html b/Quakespasm.html
index e980e5b7..4b88e245 100644
--- a/Quakespasm.html
+++ b/Quakespasm.html
@@ -18,14 +18,13 @@
 
 <P>
 <H2><A NAME="toc3">3.</A> <A HREF="Quakespasm.html#s3">Hints </A></H2>
-
 <UL>
 <LI><A NAME="toc3.1">3.1</A> <A HREF="Quakespasm.html#ss3.1">Music Playback</A>
 <LI><A NAME="toc3.2">3.2</A> <A HREF="Quakespasm.html#ss3.2">Controller Support</A>
 </UL>
+
 <P>
 <H2><A NAME="toc4">4.</A> <A HREF="Quakespasm.html#s4">Compiling and Installation</A></H2>
-
 <UL>
 <LI><A NAME="toc4.1">4.1</A> <A HREF="Quakespasm.html#ss4.1">Linux/Unix </A>
 <LI><A NAME="toc4.2">4.2</A> <A HREF="Quakespasm.html#ss4.2">Windows </A>
@@ -33,8 +32,8 @@
 <LI><A NAME="toc4.4">4.4</A> <A HREF="Quakespasm.html#ss4.4">Quake '2021 re-release' </A>
 </UL>
 <P>
-<H2><A NAME="toc5">5.</A> <A HREF="Quakespasm.html#s5">Changes</A></H2>
 
+<H2><A NAME="toc5">5.</A> <A HREF="Quakespasm.html#s5">Changes</A></H2>
 <UL>
 <LI><A NAME="toc5.1">5.1</A> <A HREF="Quakespasm.html#ss5.1">Changes in 0.94.6</A>
 <LI><A NAME="toc5.2">5.2</A> <A HREF="Quakespasm.html#ss5.2">Changes in 0.94.5</A>
@@ -219,6 +218,7 @@ Compile time options include
 <P>
 <UL>
 <LI> Server protocol size check fixes for sounds and particles.</LI>
+<LI> An invalid memory access fix in the jpg screenshot writer.</LI>
 <LI> Backported a few fixes to the bundled SDL2-2.0.22 version.</LI>
 <LI> Minor build fix for C++ compilers.</LI>
 </UL>
diff --git a/Quakespasm.txt b/Quakespasm.txt
index 0d832266..6f9374ff 100644
--- a/Quakespasm.txt
+++ b/Quakespasm.txt
@@ -269,6 +269,8 @@
 
   o  Server protocol size check fixes for sounds and particles.
 
+  o  An invalid memory access fix in the jpg screenshot writer.
+
   o  Backported a few fixes to the bundled SDL2-2.0.22 version.
 
   o  Minor build fix for C++ compilers.