[Mesa-dev] [PATCH] mesa/uniform_query: Don't write to *params if there is an error

[Matt Turner]

The GL 3.1 and ES 3.0 specs say of glGetActiveUniformsiv:
   "If an error occurs, nothing will be written to params."

So save a copy of params and restore it on error. The alternative is
making a pass through the array to check for errors before a second pass
that actually writes *params, but that seems like optimizing bad
programs at the expense of good ones. Actually, this patch sort of does
too.

Fixes es3conform's getactiveuniformsiv_for_nonexistent_uniform_indices
test.
---
 src/mesa/main/uniform_query.cpp |   13 +++++++++++--
 1 files changed, 11 insertions(+), 2 deletions(-)

Are there security implications of malloc'ing based on uniformCount?

diff --git a/src/mesa/main/uniform_query.cpp b/src/mesa/main/uniform_query.cpp
index cbdd39e..57ddf68 100644
--- a/src/mesa/main/uniform_query.cpp
+++ b/src/mesa/main/uniform_query.cpp
@@ -84,6 +84,7 @@ _mesa_GetActiveUniformsiv(GLuint program,
    GET_CURRENT_CONTEXT(ctx);
    struct gl_shader_program *shProg;
    GLsizei i;
+   GLint *saved_params;
 
    shProg = _mesa_lookup_shader_program_err(ctx, program, "glGetActiveUniform");
    if (!shProg)
@@ -95,13 +96,16 @@ _mesa_GetActiveUniformsiv(GLuint program,
       return;
    }
 
+   saved_params = (GLint *) malloc(uniformCount * sizeof(GLint));
+   memcpy(saved_params, params, uniformCount * sizeof(GLint));
+
    for (i = 0; i < uniformCount; i++) {
       GLuint index = uniformIndices[i];
       const struct gl_uniform_storage *uni = &shProg->UniformStorage[index];
 
       if (index >= shProg->NumUserUniformStorage) {
 	 _mesa_error(ctx, GL_INVALID_VALUE, "glGetActiveUniformsiv(index)");
-	 return;
+	 goto error;
       }
 
       switch (pname) {
@@ -142,9 +146,14 @@ _mesa_GetActiveUniformsiv(GLuint program,
 
       default:
 	 _mesa_error(ctx, GL_INVALID_ENUM, "glGetActiveUniformsiv(pname)");
-	 return;
+	 goto error;
       }
    }
+   free(saved_params);
+   return;
+error:
+   memcpy(params, saved_params, uniformCount * sizeof(GLint));
+   free(saved_params);
 }
 
 static bool
-- 
1.7.8.6