mem-pool: add convenience functions for strdup and strndup

fast-import had a special mem_pool_strdup() convenience function that I
want to be able to use from the new merge algorithm I am writing.  Move
it from fast-import to mem-pool, and also add a mem_pool_strndup()
while at it that I also want to use.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/mem-pool.h b/mem-pool.h
index 999d3c3a52..ca062c9070 100644
--- a/mem-pool.h
+++ b/mem-pool.h
@@ -42,6 +42,12 @@ void *mem_pool_alloc(struct mem_pool *pool, size_t len);
 void *mem_pool_calloc(struct mem_pool *pool, size_t count, size_t size);
 
 /*
+ * Allocate memory from the memory pool and copy str into it.
+ */
+char *mem_pool_strdup(struct mem_pool *pool, const char *str);
+char *mem_pool_strndup(struct mem_pool *pool, const char *str, size_t len);
+
+/*
  * Move the memory associated with the 'src' pool to the 'dst' pool. The 'src'
  * pool will be empty and not contain any memory. It still needs to be free'd
  * with a call to `mem_pool_discard`.