GLShaderContext mixing malloc and delete

[Andrew Wason]

GLShaderContext::glsl_report_shader_errors() mallocs a message buffer but then deletes it with "delete[]" instead of free(). On Mac at least this causes the app to crash with a message like:

 Python(44890,0xad2852c0) malloc: *** error for object 0x6c9a62d4: pointer being freed was not allocated

Also the info_log pointer is uninitialized and is deleted even if not allocated, so we may delete a random pointer.

So this patch uses free() instead of delete[]. Also it only frees the buffer if it was allocated. And I changed the length check to >1 - the length returned for GL_INFO_LOG_LENGTH includes the NUL char, so length of 1 would mean an empty string (and this is what my Nvidia Quadro FX 580 on Ubuntu 11.10 always returns on success).

[rdb (rdb)]

Thank you very much for the patch. I've applied it to the trunk and 1.8 branch. I've applied the same fix to the glsl_report_program_errors() method as well.