[PATCH 05/10] string-list API: make has_string() and list_lookup() "const"

["Ævar Arnfjörð Bjarmason" <avarab@gmail.com>]

Ever since these were added in the "path_list" predecessor of this API
in 6d297f81373 (Status update on merge-recursive in C, 2006-07-08)
they haven't been "const", but as the compiler validates for us adding
that attribute to them is correct.

Note that they will return a non-const "struct string_list_item *",
but the "struct string_list *" itself that's passed in can be marked
"const".

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
---
 string-list.c | 4 ++--
 string-list.h | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/string-list.c b/string-list.c
index d8957466d25..d97a8f61c02 100644
--- a/string-list.c
+++ b/string-list.c
@@ -245,7 +245,7 @@ void string_list_sort(struct string_list *list)
 	QSORT_S(list->items, list->nr, cmp_items, &sort_ctx);
 }
 
-struct string_list_item *unsorted_string_list_lookup(struct string_list *list,
+struct string_list_item *unsorted_string_list_lookup(const struct string_list *list,
 						     const char *string)
 {
 	struct string_list_item *item;
@@ -257,7 +257,7 @@ struct string_list_item *unsorted_string_list_lookup(struct string_list *list,
 	return NULL;
 }
 
-int unsorted_string_list_has_string(struct string_list *list,
+int unsorted_string_list_has_string(const struct string_list *list,
 				    const char *string)
 {
 	return unsorted_string_list_lookup(list, string) != NULL;
diff --git a/string-list.h b/string-list.h
index 7153cb79154..3589afee2ee 100644
--- a/string-list.h
+++ b/string-list.h
@@ -227,13 +227,13 @@ void string_list_sort(struct string_list *list);
  * Like `string_list_has_string()` but for unsorted lists. Linear in
  * size of the list.
  */
-int unsorted_string_list_has_string(struct string_list *list, const char *string);
+int unsorted_string_list_has_string(const struct string_list *list, const char *string);
 
 /**
  * Like `string_list_lookup()` but for unsorted lists. Linear in size
  * of the list.
  */
-struct string_list_item *unsorted_string_list_lookup(struct string_list *list,
+struct string_list_item *unsorted_string_list_lookup(const struct string_list *list,
 						     const char *string);
 /**
  * Remove an item from a string_list. The `string` pointer of the
-- 
2.38.0.1251.g3eefdfb5e7a