Mesa (7.10): glsl: Fix memory error when creating the supported version string.

[Kenneth Graunke]

Module: Mesa
Branch: 7.10
Commit: 9286d0ddd37e64c3e8c50bb7de1bd100969a5c98
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=9286d0ddd37e64c3e8c50bb7de1bd100969a5c98

Author: Kenneth Graunke <kenneth at whitecape.org>
Date:   Tue Feb  1 00:20:01 2011 -0800

glsl: Fix memory error when creating the supported version string.

Passing ralloc_vasprintf_append a 0-byte allocation doesn't work.  If
passed a non-NULL argument, ralloc calls strlen to find the end of the
string.  Since there's no terminating '\0', it runs off the end.

Fixes a crash introduced in 14880a510a1a288df0778395097d5a52806abfb0.

(cherry-picked from commit a7d350790b4d0416117bc785aa77de52e9298a01)

---

 src/glsl/glsl_parser_extras.cpp |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/src/glsl/glsl_parser_extras.cpp b/src/glsl/glsl_parser_extras.cpp
index 3a17db8..3dffb33 100644
--- a/src/glsl/glsl_parser_extras.cpp
+++ b/src/glsl/glsl_parser_extras.cpp
@@ -97,7 +97,7 @@ _mesa_glsl_parse_state::_mesa_glsl_parse_state(struct gl_context *ctx,
       ? 100 : 110;
    const unsigned highest_version =
       (ctx->API == API_OPENGL) ? ctx->Const.GLSLVersion : 100;
-   char *supported = (char *) ralloc_context(this);
+   char *supported = ralloc_strdup(this, "");
 
    for (unsigned ver = lowest_version; ver <= highest_version; ver += 10) {
       const char *const prefix = (ver == lowest_version)