(BUF_PTR_CHAR_POS): New macro.

1 files changed, 7 insertions, 0 deletions

diff --git a/src/buffer.h b/src/buffer.h
index 499a8629afa..2e2f3fbfe23 100644
--- a/src/buffer.h
+++ b/src/buffer.h
@@ -130,6 +130,13 @@ the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */
 ((ptr) - (current_buffer)->text.beg                                     \
  - (ptr - (current_buffer)->text.beg < (unsigned) GPT ? 0 : GAP_SIZE)   \
  + 1)
+
+/* Convert the address of a char in the buffer into a character position.  */
+#define BUF_PTR_CHAR_POS(buf, ptr)                      \
+((ptr) - (buf)->text.beg                                \
+ - (ptr - (buf)->text.beg < (unsigned) BUF_GPT ((buf))  \
+    ? 0 : BUF_GAP_SIZE ((buf)))                         \
+ + 1)
 
 struct buffer_text
   {