Mesa (master): glsl2: check for _NumLinkedShaders being 0

[Ian Romanick]

Module: Mesa
Branch: master
Commit: c47b289972a6c5ca0e30ff5618418e5ca91bd1ec
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=c47b289972a6c5ca0e30ff5618418e5ca91bd1ec

Author: Török Edvin <edwintorok at gmail.com>
Date:   Sat Sep  4 13:48:24 2010 +0300

glsl2: check for _NumLinkedShaders being 0

Otherwise spring 0.82+.4.0 crashes when starting a game
because prog->_LinkedShaders[0] is NULL.

This also fixes piglit test cases glsl-link-empty-prog-0[12].

---

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

diff --git a/src/glsl/linker.cpp b/src/glsl/linker.cpp
index e0823c3..02c7c29 100644
--- a/src/glsl/linker.cpp
+++ b/src/glsl/linker.cpp
@@ -1476,7 +1476,7 @@ link_shaders(GLcontext *ctx, struct gl_shader_program *prog)
 
    assign_uniform_locations(prog);
 
-   if (prog->_LinkedShaders[0]->Type == GL_VERTEX_SHADER) {
+   if (prog->_NumLinkedShaders && prog->_LinkedShaders[0]->Type == GL_VERTEX_SHADER) {
       /* FINISHME: The value of the max_attribute_index parameter is
        * FINISHME: implementation dependent based on the value of
        * FINISHME: GL_MAX_VERTEX_ATTRIBS.  GL_MAX_VERTEX_ATTRIBS must be