mesa: another fix for program/texture state validation

This fixes a regression introduced in 46ae1abbac

Break program validation into two steps, do part before texture state
validation and do the rest after:
1. Determine Vertex/Fragment _Enabled state.
2. Update texture state.
3. Determine pointers to current Vertex/Fragment programs (which may involve
generating new "fixed-function" programs).

See comments in the code for more details of the dependencies.

src/mesa/main/state.c

@@ -173,13 +173,16 @@ update_arrays( GLcontext *ctx )
 }
 
 
+/**
+ * Update the following fields:
+ *   ctx->VertexProgram._Enabled
+ *   ctx->FragmentProgram._Enabled
+ *   ctx->ATIFragmentShader._Enabled
+ * This needs to be done before texture state validation.
+ */
 static void
-update_program(GLcontext *ctx)
+update_program_enables(GLcontext *ctx)
 {
-   const struct gl_shader_program *shProg = ctx->Shader.CurrentProgram;
-   const struct gl_vertex_program *prevVP = ctx->VertexProgram._Current;
-   const struct gl_fragment_program *prevFP = ctx->FragmentProgram._Current;
-
    /* These _Enabled flags indicate if the program is enabled AND valid. */
    ctx->VertexProgram._Enabled = ctx->VertexProgram.Enabled
       && ctx->VertexProgram.Current->Base.Instructions;
@@ -187,6 +190,25 @@ update_program(GLcontext *ctx)
       && ctx->FragmentProgram.Current->Base.Instructions;
    ctx->ATIFragmentShader._Enabled = ctx->ATIFragmentShader.Enabled
       && ctx->ATIFragmentShader.Current->Instructions[0];
+}
+
+
+/**
+ * Update vertex/fragment program state.  In particular, update these fields:
+ *   ctx->VertexProgram._Current
+ *   ctx->VertexProgram._TnlProgram,
+ * These point to the highest priority enabled vertex/fragment program or are
+ * NULL if fixed-function processing is to be done.
+ *
+ * This function needs to be called after texture state validation in case
+ * we're generating a fragment program from fixed-function texture state.
+ */
+static void
+update_program(GLcontext *ctx)
+{
+   const struct gl_shader_program *shProg = ctx->Shader.CurrentProgram;
+   const struct gl_vertex_program *prevVP = ctx->VertexProgram._Current;
+   const struct gl_fragment_program *prevFP = ctx->FragmentProgram._Current;
 
    /*
     * Set the ctx->VertexProgram._Current and ctx->FragmentProgram._Current
@@ -429,6 +451,7 @@ _mesa_update_state_locked( GLcontext *ctx )
    if (MESA_VERBOSE & VERBOSE_STATE)
       _mesa_print_state("_mesa_update_state", new_state);
 
+   /* Determine which state flags effect vertex/fragment program state */
    if (ctx->FragmentProgram._MaintainTexEnvProgram) {
       prog_flags |= (_NEW_TEXTURE | _NEW_FOG | _DD_NEW_SEPARATE_SPECULAR);
    }
@@ -438,8 +461,13 @@ _mesa_update_state_locked( GLcontext *ctx )
                      _NEW_FOG | _NEW_LIGHT |
                      _MESA_NEW_NEED_EYE_COORDS);
    }
+
+   /*
+    * Now update derived state info
+    */
+
    if (new_state & prog_flags)
-      update_program( ctx );
+      update_program_enables( ctx );
 
    if (new_state & (_NEW_MODELVIEW|_NEW_PROJECTION))
       _mesa_update_modelview_project( ctx, new_state );
@@ -500,6 +528,8 @@ _mesa_update_state_locked( GLcontext *ctx )
    if (new_state & _MESA_NEW_NEED_EYE_COORDS) 
       _mesa_update_tnl_spaces( ctx, new_state );
 
+   if (new_state & prog_flags)
+      update_program( ctx );
 
    /*
     * Give the driver a chance to act upon the new_state flags.