2 files changed, 37 insertions, 0 deletions
diff --git a/src/basic/strv.c b/src/basic/strv.c
index 8282298dca..97a96e5762 100644
--- a/src/basic/strv.c
+++ b/src/basic/strv.c
@@ -558,6 +558,42 @@ int strv_extend(char ***l, const char *value) {
         return strv_consume(l, v);
 }
 
+int strv_extend_front(char ***l, const char *value) {
+        size_t n, m;
+        char *v, **c;
+
+        assert(l);
+
+        /* Like strv_extend(), but prepends rather than appends the new entry */
+
+        if (!value)
+                return 0;
+
+        n = strv_length(*l);
+
+        /* Increase and overflow check. */
+        m = n + 2;
+        if (m < n)
+                return -ENOMEM;
+
+        v = strdup(value);
+        if (!v)
+                return -ENOMEM;
+
+        c = realloc_multiply(*l, sizeof(char*), m);
+        if (!c) {
+                free(v);
+                return -ENOMEM;
+        }
+
+        memmove(c+1, c, n * sizeof(char*));
+        c[0] = v;
+        c[n+1] = NULL;
+
+        *l = c;
+        return 0;
+}
+
 char **strv_uniq(char **l) {
         char **i;
 
diff --git a/src/basic/strv.h b/src/basic/strv.h
index 7bfa54408d..f61bbb5386 100644
--- a/src/basic/strv.h
+++ b/src/basic/strv.h
@@ -50,6 +50,7 @@ int strv_extend_strv(char ***a, char **b, bool filter_duplicates);
 int strv_extend_strv_concat(char ***a, char **b, const char *suffix);
 int strv_extend(char ***l, const char *value);
 int strv_extendf(char ***l, const char *format, ...) _printf_(2,0);
+int strv_extend_front(char ***l, const char *value);
 int strv_push(char ***l, char *value);
 int strv_push_pair(char ***l, char *a, char *b);
 int strv_push_prepend(char ***l, char *value);