parser/yaboot: Fix check for image presence

In the cleanup of yaboot option state, 3fb8fb6fb, we change from
checking opt->boot_image to opt, to indicate that we're parsing an image
section.

We missed one check, which is causing a segfault due to the null opt.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>

3 files changed, 34 insertions, 1 deletions

diff --git a/discover/yaboot-parser.c b/discover/yaboot-parser.c
index 3696abf..39fba63 100644
--- a/discover/yaboot-parser.c
+++ b/discover/yaboot-parser.c
@@ -175,7 +175,8 @@ static void yaboot_process_pair(struct conf_context *conf, const char *name,
 		return;
 	}
 
-	if (!opt->boot_image) {
+	/* all other processing requires an image */
+	if (!opt) {
 		pb_log("%s: unknown name: %s\n", __func__, name);
 		return;
 	}
diff --git a/test/parser/Makefile.am b/test/parser/Makefile.am
index f1458cd..bb45a40 100644
--- a/test/parser/Makefile.am
+++ b/test/parser/Makefile.am
@@ -34,6 +34,7 @@ TESTS = \
 	test-kboot-single \
 	test-yaboot-single \
 	test-yaboot-external \
+	test-yaboot-root-global \
 	test-yaboot-rh8-ppc64 \
 	test-pxe-single \
 	test-pxe-initrd-in-append
diff --git a/test/parser/test-yaboot-root-global.c b/test/parser/test-yaboot-root-global.c
new file mode 100644
index 0000000..6d8da85
--- /dev/null
+++ b/test/parser/test-yaboot-root-global.c
@@ -0,0 +1,31 @@
+
+
+#include "parser-test.h"
+
+#if 0 /* PARSER_EMBEDDED_CONFIG */
+default=linux
+root=/dev/sda1
+
+image=/vmlinux
+	label=linux
+	initrd=/initrd
+#endif
+
+void run_test(struct parser_test *test)
+{
+	struct discover_boot_option *opt;
+	struct discover_context *ctx;
+
+	test_read_conf_embedded(test);
+	test_run_parser(test, "yaboot");
+
+	ctx = test->ctx;
+
+	check_boot_option_count(ctx, 1);
+
+	opt = get_boot_option(ctx, 0);
+
+	check_name(opt, "linux");
+	check_resolved_local_resource(opt->boot_image, ctx->device, "/vmlinux");
+	check_resolved_local_resource(opt->initrd, ctx->device, "/initrd");
+}