fix potential NULL dereference (bug 11880)

diff --git a/src/mesa/shader/shader_api.c b/src/mesa/shader/shader_api.c
index 1a931326afa3a9d5117429fb32c85ebce5368bdd..a1e73ef125c71343a9f9b62c3c560b00f5fc80c3 100644 (file)
--- a/src/mesa/shader/shader_api.c
+++ b/src/mesa/shader/shader_api.c
@@ -377,7 +377,7 @@ _mesa_attach_shader(GLcontext *ctx, GLuint program, GLuint shader)
    struct gl_shader_program *shProg
       = _mesa_lookup_shader_program(ctx, program);
    struct gl_shader *sh = _mesa_lookup_shader(ctx, shader);
-   const GLuint n = shProg->NumShaders;
+   GLuint n;
    GLuint i;
 
    if (!shProg || !sh) {
@@ -386,6 +386,8 @@ _mesa_attach_shader(GLcontext *ctx, GLuint program, GLuint shader)
       return;
    }
 
+   n = shProg->NumShaders;
+
    for (i = 0; i < n; i++) {
       if (shProg->Shaders[i] == sh) {
          /* already attached */
@@ -547,7 +549,7 @@ _mesa_detach_shader(GLcontext *ctx, GLuint program, GLuint shader)
 {
    struct gl_shader_program *shProg
       = _mesa_lookup_shader_program(ctx, program);
-   const GLuint n = shProg->NumShaders;
+   GLuint n;
    GLuint i, j;
 
    if (!shProg) {
@@ -556,6 +558,8 @@ _mesa_detach_shader(GLcontext *ctx, GLuint program, GLuint shader)
       return;
    }
 
+   n = shProg->NumShaders;
+
    for (i = 0; i < n; i++) {
       if (shProg->Shaders[i]->Name == shader) {
          /* found it */