pickaxe: honor -i when used with -S and --pickaxe-regex

accccde4 (pickaxe: allow -i to search in patch case-insensitively)
allowed case-insenitive matching for -G and -S, but for the latter
only if fixed string matching is used.  Allow it for -S and regular
expression matching as well to make the support complete.

Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diffcore-pickaxe.c

@@ -237,7 +237,10 @@ static void diffcore_pickaxe_count(struct diff_options *o)
 
 	if (opts & DIFF_PICKAXE_REGEX) {
 		int err;
-		err = regcomp(&regex, needle, REG_EXTENDED | REG_NEWLINE);
+		int cflags = REG_EXTENDED | REG_NEWLINE;
+		if (DIFF_OPT_TST(o, PICKAXE_IGNORE_CASE))
+			cflags |= REG_ICASE;
+		err = regcomp(&regex, needle, cflags);
 		if (err) {
 			/* The POSIX.2 people are surely sick */
 			char errbuf[1024];

t/t4209-log-pickaxe.sh

@@ -88,6 +88,11 @@ test_log	expect_second	-S Picked
 test_log_icase	expect_second	-S picked
 test_log_icase	expect_nomatch	-S pickle
 
+test_log	expect_nomatch	-S p.cked --pickaxe-regex
+test_log	expect_second	-S P.cked --pickaxe-regex
+test_log_icase	expect_second	-S p.cked --pickaxe-regex
+test_log_icase	expect_nomatch	-S p.ckle --pickaxe-regex
+
 test_expect_success 'log -S --textconv (missing textconv tool)' '
 	echo "* diff=test" >.gitattributes &&
 	test_must_fail git -c diff.test.textconv=missing log -Sfoo &&