Find next merge directly

Find merges by traversing lines directly. Instead of collecting
hte merges like matches, the next merge is determined starting
from the current line. Whether the search wraps around is
controlled by wrap-search.

As per review: #525 (comment)

src/search.c

@@ -55,36 +55,6 @@ find_matches(struct view *view)
 	return true;
 }
 
-static bool
-find_merges(struct view *view)
-{
-	size_t lineno;
-
-	for (lineno = 0; lineno < view->lines; lineno++) {
-		struct line *line = &view->line[lineno];
-		struct commit *commit = line->data;
-		struct graph_canvas *canvas = &commit->graph;
-		struct view_column_data column_data;
-
-		if (!view->ops->get_column_data(view, line, &column_data))
-			continue;
-
-		if (column_data.graph && !column_data.graph->is_merge(canvas))
-			continue;
-
-		if (!realloc_unsigned_ints(&view->matched_line, view->matched_lines, 1))
-			return false;
-
-		view->line[lineno].search_result = true;
-		view->matched_line[view->matched_lines++] = lineno;
-	}
-
-	/* Clear and show highlighted results. */
-	redraw_view_from(view, 0);
-
-	return true;
-}
-
 static enum status_code find_next_match(struct view *view, enum request request);
 
 static enum status_code
@@ -191,6 +161,44 @@ find_next(struct view *view, enum request request)
 	report("%s", get_status_message(code));
 }
 
+static enum status_code
+find_next_merge_line(struct view *view, int direction, bool wrapped)
+{
+	enum status_code code = -1;
+	/*size_t lineno = view->pos.lineno + direction;*/
+	/*for (; lineno < view->lines; lineno = lineno + direction % view->lines)*/
+	ssize_t dist;
+	size_t max;
+	if (wrapped)
+		max = view->lines;
+	else
+		max = direction > 0 ? view->lines - view->pos.lineno
+				    : view->pos.lineno;
+	for (dist = direction; abs(dist) < max; dist += direction) {
+		ssize_t lineno = view->pos.lineno + dist;
+		struct line *line = &view->line[lineno];
+		struct commit *commit = line->data;
+		struct graph_canvas *canvas = &commit->graph;
+		struct view_column_data column_data;
+
+		if (lineno < 0)
+			lineno += view->lines;
+		else if (lineno >= view->lines)
+			lineno -= view->lines;
+
+		if (!view->ops->get_column_data(view, line, &column_data))
+			continue;
+
+		if (column_data.graph && !column_data.graph->is_merge(canvas))
+			continue;
+
+		select_view_line(view, lineno);
+		code = SUCCESS;
+		break;
+	}
+	return code;
+}
+
 static enum status_code
 find_next_merge(struct view *view, enum request request)
 {
@@ -210,13 +218,7 @@ find_next_merge(struct view *view, enum request request)
 		return error("Invalid request searching for next merge");
 	}
 
-	if (!view->matched_lines && !find_merges(view))
-		return ERROR_OUT_OF_MEMORY;
-
-	code = find_next_match_line(view, direction, false);
-	if (code != SUCCESS && opt_wrap_search)
-		code = find_next_match_line(view, direction, true);
-
+	code = find_next_merge_line(view, direction, opt_wrap_search);
 
 	return code == SUCCESS ? code : success("No merge commit found");
 }