From: Steinar H. Gunderson <sgunderson@bigfoot.com>
Date: Sun, 6 Apr 2014 21:58:54 +0000 (+0200)
Subject: Properly restore the LC_NUMERIC locale after finalizing.
X-Git-Tag: 1.1~2
X-Git-Url: https://git.sesse.net/?p=movit;a=commitdiff_plain;h=041500231054441f851b7c7260ab815dae6fb368;hp=1b46606b3c5d6a7a97528a53d0309d3cd04df62b

Properly restore the LC_NUMERIC locale after finalizing.

There were two issues here:

 1. setlocale(LC_NUMERIC, "C") always returns C, not the previous
    locale.
 2. The return value of setlocale() may point into static storage,
    which may be corrupted when we call into libGL, if e.g.
    the shader compiler calls setlocale() on its own.

Patch by Jean-Baptiste Mardelle.
---

diff --git a/effect_chain.cpp b/effect_chain.cpp
index 0a01bd3..a5c3bbd 100644
--- a/effect_chain.cpp
+++ b/effect_chain.cpp
@@ -1332,7 +1332,11 @@ void EffectChain::finalize()
 {
 	// Save the current locale, and set it to C, so that we can output decimal
 	// numbers with printf and be sure to get them in the format mandated by GLSL.
-	char *saved_locale = setlocale(LC_NUMERIC, "C");
+	// Note that the OpenGL driver might call setlocale() behind-the-scenes,
+	// and that might corrupt the returned pointer, so we need to take our own
+	// copy of it here.
+	char *saved_locale = strdup(setlocale(LC_NUMERIC, NULL));
+	setlocale(LC_NUMERIC, "C");
 
 	// Output the graph as it is before we do any conversions on it.
 	output_dot("step0-start.dot");
@@ -1397,6 +1401,7 @@ void EffectChain::finalize()
 	
 	finalized = true;
 	setlocale(LC_NUMERIC, saved_locale);
+	free(saved_locale);
 }
 
 void EffectChain::render_to_fbo(GLuint dest_fbo, unsigned width, unsigned height)