mesa: new MESA_EXTENSION_MAX_YEAR env var
If set to year X, only report extensions up to that year. This is a
work-around for games that try to copy the extensions string to a fixed
size buffer and overflow. If a game was released in year X, setting
MESA_EXTENSION_MAX_YEAR to that year will likely fix the problem.
diff --git a/docs/envvars.html b/docs/envvars.html
index c8be843..986d2f8 100644
--- a/docs/envvars.html
+++ b/docs/envvars.html
@@ -49,6 +49,15 @@
<li>MESA_EXTENSION_OVERRIDE - can be used to enable/disable extensions.
A value such as "GL_EXT_foo -GL_EXT_bar" will enable the GL_EXT_foo extension
and disable the GL_EXT_bar extension.
+<li>MESA_EXTENSION_MAX_YEAR - The GL_EXTENSIONS string returned by Mesa is sorted
+by extension year.
+If this variable is set to year X, only extensions defined on or before year
+X will be reported.
+This is to work-around a bug in some games where the extension string is
+copied into a fixed-size buffer without truncating.
+If the extension string is too long, the buffer overrun can cause the game
+to crash.
+This is a work-around for that.
<li>MESA_GLSL - <a href="shading.html#envvars">shading language compiler options</a>
</ul>