avoid segfault on submodule.*.path set to an empty "true"jl/some-submodule-config-are-not-boolean

Git fails due to a segmentation fault if a submodule path is empty.
Here is an example .gitmodules that will cause a segmentation fault:

    [submodule "foo-module"]
      path
      url = http://host/repo.git
    $ git status
    Segmentation fault (core dumped)

This is because the parsing of "submodule.*.path" is not prepared to
see a value-less "true" and assumes that the value is always
non-NULL (parsing of "ignore" has the same problem).

Fix it by checking the NULL-ness of value and complain with
config_error_nonbool().

Signed-off-by: Jharrod LaFon <jlafon@eyesopen.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/submodule.c b/submodule.c
index 975bc87e48..8f7515ed66 100644
--- a/submodule.c
+++ b/submodule.c
@@ -134,6 +134,9 @@ int parse_submodule_config_option(const char *var, const char *value)
 		return 0;
 
 	if (!strcmp(key, "path")) {
+		if (!value)
+			return config_error_nonbool(var);
+
 		config = unsorted_string_list_lookup(&config_name_for_path, value);
 		if (config)
 			free(config->util);
@@ -151,6 +154,9 @@ int parse_submodule_config_option(const char *var, const char *value)
 	} else if (!strcmp(key, "ignore")) {
 		char *name_cstr;
 
+		if (!value)
+			return config_error_nonbool(var);
+
 		if (strcmp(value, "untracked") && strcmp(value, "dirty") &&
 		    strcmp(value, "all") && strcmp(value, "none")) {
 			warning("Invalid parameter \"%s\" for config option \"submodule.%s.ignore\"", value, var);