resolve: fix NULL deref on strv comparison

A strv might be NULL if it is empty. The txt.strings comparison doesn't
take that into account. Introduce strv_equal() to provide a proper helper
for this and fix resolve to use it.

Thanks to Stanisław Pitucha <viraptor@gmail.com> for reporting this!

1 files changed, 2 insertions, 0 deletions

diff --git a/src/shared/strv.h b/src/shared/strv.h
index 47618bd26c..774c67a8c8 100644
--- a/src/shared/strv.h
+++ b/src/shared/strv.h
@@ -49,6 +49,8 @@ int strv_consume_prepend(char ***l, char *value);
 char **strv_remove(char **l, const char *s);
 char **strv_uniq(char **l);
 
+bool strv_equal(char **a, char **b);
+
 #define strv_contains(l, s) (!!strv_find((l), (s)))
 
 char **strv_new(const char *x, ...) _sentinel_;