common: New function get_membuf_shrink.

* common/membuf.c (get_membuf_shrink): New.

2 files changed, 26 insertions, 0 deletions

diff --git a/common/membuf.c b/common/membuf.c
index 02f1b2795..884c08cf3 100644
--- a/common/membuf.c
+++ b/common/membuf.c
@@ -170,6 +170,31 @@ get_membuf (membuf_t *mb, size_t *len)
 }
 
 
+/* Same as get_membuf but shrinks the reallocated space to the
+   required size.  */
+void *
+get_membuf_shrink (membuf_t *mb, size_t *len)
+{
+  void *p, *pp;
+  size_t dummylen;
+
+  if (!len)
+    len = &dummylen;
+
+  p = get_membuf (mb, &len);
+  if (!p)
+    return NULL;
+  if (len)
+    {
+      pp = xtryrealloc (p, len);
+      if (pp)
+        p = pp;
+    }
+
+  return p;
+}
+
+
 /* Peek at the membuf MB.  On success a pointer to the buffer is
    returned which is valid until the next operation on MB.  If LEN is
    not NULL the current LEN of the buffer is stored there.  On error
diff --git a/common/membuf.h b/common/membuf.h
index bf4cf3687..dfa236d82 100644
--- a/common/membuf.h
+++ b/common/membuf.h
@@ -57,6 +57,7 @@ void put_membuf_str (membuf_t *mb, const char *string);
 void put_membuf_printf (membuf_t *mb, const char *format,
                         ...) JNLIB_GCC_A_PRINTF(2,3);
 void *get_membuf (membuf_t *mb, size_t *len);
+void *get_membuf_shrink (membuf_t *mb, size_t *len);
 const void *peek_membuf (membuf_t *mb, size_t *len);
 
 #endif /*GNUPG_COMMON_MEMBUF_H*/