[PATCH] completion: search through all open buffers for possible completions

This allows one to complete words or names that are used or defined
in another file that is open in another buffer.

This fulfills https://savannah.gnu.org/bugs/?61691.
Requested-by: Tasos Papastylianou <[email protected]>

Original-patch-by: Marco Diego Aurélio Mesquita <[email protected]>
---
 src/text.c | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/src/text.c b/src/text.c
index 38041add..2222a5b4 100644
--- a/src/text.c
+++ b/src/text.c
@@ -3061,12 +3061,14 @@ char *copy_completion(char *text)
 	return word;
 }
 
-/* Look at the fragment the user has typed, then search the current buffer for
+/* Look at the fragment the user has typed, then search all buffers for
  * the first word that starts with this fragment, and tentatively complete the
  * fragment.  If the user types 'Complete' again, search and paste the next
  * possible completion. */
 void complete_a_word(void)
 {
+	static openfilestruct *scouring = NULL;
+		/* The buffer that is being searched for possible completions. */
 	char *shard, *completion = NULL;
 	size_t start_of_shard, shard_length = 0;
 	size_t i = 0, j = 0;
@@ -3089,6 +3091,7 @@ void complete_a_word(void)
 		openfile->last_action = OTHER;
 
 		/* Initialize the starting point for searching. */
+		scouring = openfile;
 		pletion_line = openfile->filetop;
 		pletion_x = 0;
 
@@ -3200,9 +3203,17 @@ void complete_a_word(void)
 
 		pletion_line = pletion_line->next;
 		pletion_x = 0;
+
+#ifdef ENABLE_MULTIBUFFER
+		/* When at end of buffer and there is another, search that one. */
+		if (pletion_line == NULL && scouring->next != openfile) {
+			scouring = scouring->next;
+			pletion_line = scouring->filetop;
+		}
+#endif
 	}
 
-	/* The search has reached the end of the file. */
+	/* The search has gone through all buffers. */
 	if (list_of_completions != NULL) {
 		edit_refresh();
 		statusline(AHEM, _("No further matches"));
-- 
2.35.3