2 files changed, 8 insertions, 3 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index 4613192187e..2677f03944f 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -2,6 +2,11 @@
 
         Integer and memory overflow issues (Bug#9196).
 
+        * doc.c (get_doc_string): Rework so that
+        get_doc_string_buffer_size is the actual buffer size, rather than
+        being 1 less than the actual buffer size; this makes xpalloc more
+        convenient.
+
         * image.c (x_allocate_bitmap_record, cache_image):
         * xselect.c (Fx_register_dnd_atom):
         Simplify previous changes by using xpalloc.
diff --git a/src/doc.c b/src/doc.c
index eb8ff3c2521..83e943c42b8 100644
--- a/src/doc.c
+++ b/src/doc.c
@@ -166,19 +166,19 @@ get_doc_string (Lisp_Object filepos, int unibyte, int definition)
   p = get_doc_string_buffer;
   while (1)
     {
-      ptrdiff_t space_left = (get_doc_string_buffer_size
+      ptrdiff_t space_left = (get_doc_string_buffer_size - 1
                               - (p - get_doc_string_buffer));
       int nread;
 
       /* Allocate or grow the buffer if we need to.  */
-      if (space_left == 0)
+      if (space_left <= 0)
         {
           ptrdiff_t in_buffer = p - get_doc_string_buffer;
           get_doc_string_buffer =
             xpalloc (get_doc_string_buffer, &get_doc_string_buffer_size,
                      16 * 1024, -1, 1);
           p = get_doc_string_buffer + in_buffer;
-          space_left = (get_doc_string_buffer_size
+          space_left = (get_doc_string_buffer_size - 1
                         - (p - get_doc_string_buffer));
         }