rev-list/log: factor out revision mark generation

Currently, we have identical code for generating revision marks ('<',
'>', '-') in 5 places.

Factor out the code to a single function get_revision_mark() for easier
maintenance and extensibility.

Note that the check for !!revs in graph.c (which gets removed
effectively by this patch) is superfluous.

Signed-off-by: Michael J Gruber <git@drmicha.warpmail.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/rev-list.c

@@ -64,18 +64,8 @@ static void show_commit(struct commit *commit, void *data)
 	if (info->header_prefix)
 		fputs(info->header_prefix, stdout);
 
-	if (!revs->graph) {
-		if (commit->object.flags & BOUNDARY)
-			putchar('-');
-		else if (commit->object.flags & UNINTERESTING)
-			putchar('^');
-		else if (revs->left_right) {
-			if (commit->object.flags & SYMMETRIC_LEFT)
-				putchar('<');
-			else
-				putchar('>');
-		}
-	}
+	if (!revs->graph)
+		fputs(get_revision_mark(revs, commit), stdout);
 	if (revs->abbrev_commit && revs->abbrev)
 		fputs(find_unique_abbrev(commit->object.sha1, revs->abbrev),
 		      stdout);

graph.c

@@ -798,22 +798,9 @@ static void graph_output_commit_char(struct git_graph *graph, struct strbuf *sb)
 	}
 
 	/*
-	 * If revs->left_right is set, print '<' for commits that
-	 * come from the left side, and '>' for commits from the right
-	 * side.
+	 * get_revision_mark() handles all other cases without assert()
 	 */
-	if (graph->revs && graph->revs->left_right) {
-		if (graph->commit->object.flags & SYMMETRIC_LEFT)
-			strbuf_addch(sb, '<');
-		else
-			strbuf_addch(sb, '>');
-		return;
-	}
-
-	/*
-	 * Print '*' in all other cases
-	 */
-	strbuf_addch(sb, '*');
+	strbuf_addstr(sb, get_revision_mark(graph->revs, graph->commit));
 }
 
 /*

log-tree.c

@@ -380,18 +380,8 @@ void show_log(struct rev_info *opt)
 	if (!opt->verbose_header) {
 		graph_show_commit(opt->graph);
 
-		if (!opt->graph) {
-			if (commit->object.flags & BOUNDARY)
-				putchar('-');
-			else if (commit->object.flags & UNINTERESTING)
-				putchar('^');
-			else if (opt->left_right) {
-				if (commit->object.flags & SYMMETRIC_LEFT)
-					putchar('<');
-				else
-					putchar('>');
-			}
-		}
+		if (!opt->graph)
+			fputs(get_revision_mark(opt, commit), stdout);
 		fputs(find_unique_abbrev(commit->object.sha1, abbrev_commit), stdout);
 		if (opt->print_parents)
 			show_parents(commit, abbrev_commit);
@@ -448,18 +438,8 @@ void show_log(struct rev_info *opt)
 		if (opt->commit_format != CMIT_FMT_ONELINE)
 			fputs("commit ", stdout);
 
-		if (!opt->graph) {
-			if (commit->object.flags & BOUNDARY)
-				putchar('-');
-			else if (commit->object.flags & UNINTERESTING)
-				putchar('^');
-			else if (opt->left_right) {
-				if (commit->object.flags & SYMMETRIC_LEFT)
-					putchar('<');
-				else
-					putchar('>');
-			}
-		}
+		if (!opt->graph)
+			fputs(get_revision_mark(opt, commit), stdout);
 		fputs(find_unique_abbrev(commit->object.sha1, abbrev_commit),
 		      stdout);
 		if (opt->print_parents)

pretty.c

@@ -859,11 +859,7 @@ static size_t format_commit_one(struct strbuf *sb, const char *placeholder,
 		                              c->abbrev_parent_hashes.off;
 		return 1;
 	case 'm':		/* left/right/bottom */
-		strbuf_addch(sb, (commit->object.flags & BOUNDARY)
-		                 ? '-'
-		                 : (commit->object.flags & SYMMETRIC_LEFT)
-		                 ? '<'
-		                 : '>');
+		strbuf_addstr(sb, get_revision_mark(NULL, commit));
 		return 1;
 	case 'd':
 		format_decoration(sb, commit);

revision.c

@@ -2263,3 +2263,19 @@ struct commit *get_revision(struct rev_info *revs)
 		graph_update(revs->graph, c);
 	return c;
 }
+
+char *get_revision_mark(const struct rev_info *revs, const struct commit *commit)
+{
+	if (commit->object.flags & BOUNDARY)
+		return "-";
+	else if (commit->object.flags & UNINTERESTING)
+		return "^";
+	else if (!revs || revs->left_right) {
+		if (commit->object.flags & SYMMETRIC_LEFT)
+			return "<";
+		else
+			return ">";
+	} else if (revs->graph)
+		return "*";
+	return "";
+}

revision.h

@@ -165,6 +165,7 @@ extern int handle_revision_arg(const char *arg, struct rev_info *revs,int flags,
 
 extern int prepare_revision_walk(struct rev_info *revs);
 extern struct commit *get_revision(struct rev_info *revs);
+extern char *get_revision_mark(const struct rev_info *revs, const struct commit *commit);
 
 extern void mark_parents_uninteresting(struct commit *commit);
 extern void mark_tree_uninteresting(struct tree *tree);