Merge branch 'tr/line-log'

Fix "log -L" command line parsing bugs.

* tr/line-log:
  t4211: fix incorrect rebase at f8395ed (range-set: satisfy non-empty ranges invariant)
  line-log: fix "log -LN" crash when N is last line of file
  range-set: satisfy non-empty ranges invariant
  t4211: demonstrate crash when first -L encountered is empty range
  t4211: demonstrate empty -L range crash
  range-set: fix sort_and_merge_range_set() corner case bug

line-log.c

@@ -110,12 +110,14 @@ static void range_set_check_invariants(struct range_set *rs)
 static void sort_and_merge_range_set(struct range_set *rs)
 {
 	int i;
-	int o = 1; /* output cursor */
+	int o = 0; /* output cursor */
 
 	qsort(rs->ranges, rs->nr, sizeof(struct range), range_cmp);
 
-	for (i = 1; i < rs->nr; i++) {
-		if (rs->ranges[i].start <= rs->ranges[o-1].end) {
+	for (i = 0; i < rs->nr; i++) {
+		if (rs->ranges[i].start == rs->ranges[i].end)
+			continue;
+		if (o > 0 && rs->ranges[i].start <= rs->ranges[o-1].end) {
 			if (rs->ranges[o-1].end < rs->ranges[i].end)
 				rs->ranges[o-1].end = rs->ranges[i].end;
 		} else {
@@ -297,6 +299,7 @@ static void line_log_data_insert(struct line_log_data **list,
 	p = xcalloc(1, sizeof(struct line_log_data));
 	p->path = path;
 	range_set_append(&p->ranges, begin, end);
+	sort_and_merge_range_set(&p->ranges);
 	if (ip) {
 		p->next = ip->next;
 		ip->next = p;

t/t4211-line-log.sh

@@ -64,4 +64,17 @@ test_bad_opts "-L 1,1000:b.c" "has only.*lines"
 test_bad_opts "-L :b.c" "argument.*not of the form"
 test_bad_opts "-L :foo:b.c" "no match"
 
+# There is a separate bug when an empty -L range is the first -L encountered,
+# thus to demonstrate this particular bug, the empty -L range must follow a
+# non-empty -L range.
+test_expect_success '-L {empty-range} (any -L)' '
+	n=$(expr $(wc -l <b.c) + 1) &&
+	git log -L1,1:b.c -L$n:b.c
+'
+
+test_expect_success '-L {empty-range} (first -L)' '
+	n=$(expr $(wc -l <b.c) + 1) &&
+	git log -L$n:b.c
+'
+
 test_done