strv: add strv_remove_strv()

This is to strv_remove() what strv_extend_strv() is to strv_extend()

src/basic/strv.c

@@ -812,16 +812,14 @@ bool strv_is_uniq(char * const *l) {
 }
 
 char** strv_remove(char **l, const char *s) {
-        char **f, **t;
-
         if (!l)
                 return NULL;
 
         assert(s);
 
-        /* Drops every occurrence of s in the string list, edits
-         * in-place. */
+        /* Drops every occurrence of s in the string list, edits in-place. */
 
+        char **f, **t;
         for (f = t = l; *f; f++)
                 if (streq(*f, s))
                         free(*f);
@@ -832,6 +830,17 @@ char** strv_remove(char **l, const char *s) {
         return l;
 }
 
+char** strv_remove_strv(char **l, char *const*ll) {
+
+        if (strv_isempty(l))
+                return l;
+
+        STRV_FOREACH(i, ll)
+                strv_remove(l, *i);
+
+        return l;
+}
+
 bool strv_overlap(char * const *a, char * const *b) {
         POINTER_MAY_BE_NULL(a);
         POINTER_MAY_BE_NULL(b);

src/basic/strv.h

@@ -85,6 +85,7 @@ int strv_consume_pair(char ***l, char *a, char *b);
 int strv_consume_prepend(char ***l, char *value);
 
 char** strv_remove(char **l, const char *s);
+char** strv_remove_strv(char **l, char *const*ll);
 char** strv_uniq(char **l);
 bool strv_is_uniq(char * const *l) _pure_;
 

src/test/test-strv.c

@@ -510,6 +510,26 @@ TEST(strv_overlap) {
         assert_se(!strv_overlap((char **)input_table, (char**)input_table_unique));
 }
 
+TEST(strv_remove_strv) {
+        _cleanup_strv_free_ char **l = NULL;
+
+        ASSERT_OK(strv_extend_strv(&l, STRV_MAKE("one", "two", "three", "four"), false));
+
+        ASSERT_PTR_EQ(strv_remove_strv(l, STRV_MAKE("two", "four")), l);
+        ASSERT_TRUE(strv_equal(l, STRV_MAKE("one", "three")));
+
+        /* Removing entries not present is a no-op. */
+        ASSERT_PTR_EQ(strv_remove_strv(l, STRV_MAKE("nope")), l);
+        ASSERT_TRUE(strv_equal(l, STRV_MAKE("one", "three")));
+
+        /* Empty removal list leaves the list untouched. */
+        ASSERT_PTR_EQ(strv_remove_strv(l, STRV_EMPTY), l);
+        ASSERT_TRUE(strv_equal(l, STRV_MAKE("one", "three")));
+
+        /* Removing from an empty/NULL list is fine. */
+        ASSERT_NULL(strv_remove_strv(NULL, STRV_MAKE("one")));
+}
+
 TEST(strv_sort) {
         const char* input_table[] = {
                 "durian",