[PATCH v3 5/8] string-list: create string_list_append_all

[Denton Liu <liu.denton@gmail.com>]

In a future patch, we'll need to take one string_list and append it to
the end of another. Create the `string_list_append_all` function which
does this.

Signed-off-by: Denton Liu <liu.denton@gmail.com>
---
 string-list.c | 9 +++++++++
 string-list.h | 7 +++++++
 2 files changed, 16 insertions(+)

diff --git a/string-list.c b/string-list.c
index a917955fbd..e63d58fbd2 100644
--- a/string-list.c
+++ b/string-list.c
@@ -215,6 +215,15 @@ struct string_list_item *string_list_append(struct string_list *list,
 			list->strdup_strings ? xstrdup(string) : (char *)string);
 }
 
+void string_list_append_all(struct string_list *list,
+			    const struct string_list *append_list)
+{
+	struct string_list_item *item;
+	ALLOC_GROW(list->items, list->nr + append_list->nr, list->alloc);
+	for_each_string_list_item(item, append_list)
+		string_list_append(list, item->string);
+}
+
 /*
  * Encapsulate the compare function pointer because ISO C99 forbids
  * casting from void * to a function pointer and vice versa.
diff --git a/string-list.h b/string-list.h
index f964399949..8227e00e6a 100644
--- a/string-list.h
+++ b/string-list.h
@@ -208,6 +208,13 @@ struct string_list_item *string_list_append(struct string_list *list, const char
  */
 struct string_list_item *string_list_append_nodup(struct string_list *list, char *string);
 
+/**
+ * Add all strings in append_list to list.  If list->strdup_string is
+ * set, then each string is copied; otherwise the new string_list_entry
+ * refers to the entry in the append_list.
+ */
+void string_list_append_all(struct string_list *list, const struct string_list *append_list);
+
 /**
  * Sort the list's entries by string value in `strcmp()` order.
  */
-- 
2.22.0.rc1.169.g49223abbf8