Merge branch 'tm/line-log-first-parent'

"git log --first-parent -L..." used to crash.

* tm/line-log-first-parent:
  line-log: fix crash when --first-parent is used

Author: gitster

line-log.c

@@ -1141,6 +1141,9 @@ static int process_ranges_merge_commit(struct rev_info *rev, struct commit *comm
 	int i;
 	int nparents = commit_list_count(commit->parents);
 
+	if (nparents > 1 && rev->first_parent_only)
+		nparents = 1;
+
 	diffqueues = xmalloc(nparents * sizeof(*diffqueues));
 	cand = xmalloc(nparents * sizeof(*cand));
 	parents = xmalloc(nparents * sizeof(*parents));

t/t4211-line-log.sh

@@ -94,4 +94,9 @@ test_expect_success '-L ,Y (Y == nlines + 2)' '
 	test_must_fail git log -L ,$n:b.c
 '
 
+test_expect_success '-L with --first-parent and a merge' '
+	git checkout parallel-change &&
+	git log --first-parent -L 1,1:b.c
+'
+
 test_done