wt-status: also abbreviate 'merge' and 'fixup -C' lines during rebase

When "git status" is invoked during a rebase, we print the last commands
done and the next commands to do, and abbreviate commit hashes found in
those lines. However, we only abbreviate hashes in 'pick', 'squash' and
plain 'fixup' lines, not those in 'merge -C' and 'fixup -C' lines, as
the parsing done in wt-status.c::abbrev_oid_in_line is not prepared for
such lines.

Improve the parsing done by this function by special casing 'fixup' and
'merge' such that the hash to abbreviate is the string found in the
third field of 'split', instead of the second one for other commands.
Introduce a 'hash' strbuf pointer to point to the correct field in all
cases.

Signed-off-by: Philippe Blain <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: phil-blain

wt-status.c

@@ -1342,9 +1342,11 @@ static int split_commit_in_progress(struct wt_status *s)
 
 /*
  * Turn
- * "pick d6a2f0303e897ec257dd0e0a39a5ccb709bc2047 some message"
+ * "pick d6a2f0303e897ec257dd0e0a39a5ccb709bc2047 some message" and
+ * "merge -C d6a2f0303e897ec257dd0e0a39a5ccb709bc2047 some-branch"
  * into
- * "pick d6a2f03 some message"
+ * "pick d6a2f03 some message" and
+ * "merge -C d6a2f03 some-branch"
  *
  * The function assumes that the line does not contain useless spaces
  * before or after the command.
@@ -1360,20 +1362,31 @@ static void abbrev_oid_in_line(struct strbuf *line)
 	    starts_with(line->buf, "l "))
 		return;
 
-	split = strbuf_split_max(line, ' ', 3);
+	split = strbuf_split_max(line, ' ', 4);
 	if (split[0] && split[1]) {
 		struct object_id oid;
-
+		struct strbuf *hash;
+
+		if ((!strcmp(split[0]->buf, "merge ") ||
+		     !strcmp(split[0]->buf, "m "    ) ||
+		     !strcmp(split[0]->buf, "fixup ") ||
+		     !strcmp(split[0]->buf, "f "    )) &&
+		    (!strcmp(split[1]->buf, "-C ") ||
+		     !strcmp(split[1]->buf, "-c "))) {
+			hash = split[2];
+		} else {
+			hash = split[1];
+		}
 		/*
 		 * strbuf_split_max left a space. Trim it and re-add
 		 * it after abbreviation.
 		 */
-		strbuf_trim(split[1]);
-		if (!repo_get_oid(the_repository, split[1]->buf, &oid)) {
-			strbuf_reset(split[1]);
-			strbuf_add_unique_abbrev(split[1], &oid,
+		strbuf_trim(hash);
+		if (!repo_get_oid(the_repository, hash->buf, &oid)) {
+			strbuf_reset(hash);
+			strbuf_add_unique_abbrev(hash, &oid,
 						 DEFAULT_ABBREV);
-			strbuf_addch(split[1], ' ');
+			strbuf_addch(hash, ' ');
 			strbuf_reset(line);
 			for (i = 0; split[i]; i++)
 				strbuf_addbuf(line, split[i]);