2 files changed, 12 insertions, 2 deletions
diff --git a/src/mesa/shader/arbprogram.c b/src/mesa/shader/arbprogram.c
index 91fb691038..bff80d7ee3 100644
--- a/src/mesa/shader/arbprogram.c
+++ b/src/mesa/shader/arbprogram.c
@@ -195,13 +195,15 @@ _mesa_GetVertexAttribPointervARB(GLuint index, GLenum pname, GLvoid **pointer)
 GLboolean GLAPIENTRY
 _mesa_IsProgramARB(GLuint id)
 {
+   struct gl_program *prog = NULL; 
    GET_CURRENT_CONTEXT(ctx);
    ASSERT_OUTSIDE_BEGIN_END_WITH_RETVAL(ctx, GL_FALSE);
 
    if (id == 0)
       return GL_FALSE;
 
-   if (_mesa_lookup_program(ctx, id))
+   prog = _mesa_lookup_program(ctx, id);
+   if (prog && (prog != &_mesa_DummyProgram))
       return GL_TRUE;
    else
       return GL_FALSE;
@@ -765,6 +767,7 @@ void GLAPIENTRY
 _mesa_GetProgramStringARB(GLenum target, GLenum pname, GLvoid *string)
 {
    const struct gl_program *prog;
+   char *dst = (char *) string;
    GET_CURRENT_CONTEXT(ctx);
 
    if (!ctx->_CurrentProgram)
@@ -788,5 +791,8 @@ _mesa_GetProgramStringARB(GLenum target, GLenum pname, GLvoid *string)
       return;
    }
 
-   _mesa_memcpy(string, prog->String, _mesa_strlen((char *) prog->String));
+   if (prog->String)
+      _mesa_memcpy(dst, prog->String, _mesa_strlen((char *) prog->String));
+   else
+      *dst = '\0';
 }
diff --git a/src/mesa/shader/program.c b/src/mesa/shader/program.c
index 789d36eba0..ddfad47b89 100644
--- a/src/mesa/shader/program.c
+++ b/src/mesa/shader/program.c
@@ -207,6 +207,7 @@ _mesa_init_program_struct( GLcontext *ctx, struct gl_program *prog,
       prog->Target = target;
       prog->Resident = GL_TRUE;
       prog->RefCount = 1;
+      prog->Format = GL_PROGRAM_FORMAT_ASCII_ARB;
    }
 
    return prog;
@@ -284,6 +285,9 @@ _mesa_delete_program(GLcontext *ctx, struct gl_program *prog)
    (void) ctx;
    ASSERT(prog);
 
+   if (prog == &_mesa_DummyProgram)
+      return;
+                 
    if (prog->String)
       _mesa_free(prog->String);