glslparsertest: Avoid uninitialized vars in parse_glsl_version_number.

Previously, if the user specified an ill-formed GLSL version number
(or the implementation supplied an ill-formed number in its response
to glGetString(GL_SHADING_LANGUAGE_VERSION)), glslparsertest would
access uninitialized variables, resulting in unpredictable (and often
confusing) behaviour.

With this patch, glslparser test accepts version numbers either of the
form "<int>" or "<int>.<int>".  Ill-formed version numbers lead to a
test failure.

Reviewed-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Chad Versace <chad.versace@linux.intel.com>
Reviewed-by: Tom Gall <tom.gall@linaro.org>

v2: Add comment explaining the use of sscanf(...) == 0.

1 files changed, 11 insertions, 3 deletions

diff --git a/tests/glslparsertest/glslparsertest.c b/tests/glslparsertest/glslparsertest.c
index 0903f68f1..cd5aa36e9 100644
--- a/tests/glslparsertest/glslparsertest.c
+++ b/tests/glslparsertest/glslparsertest.c
@@ -339,10 +339,18 @@ int process_options(int argc, char **argv)
 static unsigned
 parse_glsl_version_number(const char *str)
 {
-	unsigned major;
-	unsigned minor;
+	unsigned major = 0;
+	unsigned minor = 0;
+
+	/* Accept a return value of either 1 or 2 from sscanf(), so
+	 * that the version number may be supplied as either "<int>"
+	 * or "<int>.<int>".
+	 */
+	if (sscanf(str, "%u.%u", &major, &minor) == 0) {
+		printf("Ill-formed GLSL version number: %s\n", str);
+		piglit_report_result(PIGLIT_FAIL);
+	}
 
-	sscanf(str, "%u.%u", &major, &minor);
 	return (major * 100) + minor;
 }