[PATCH] tr: an escaped dash doesn't indicate a range

[Ron Yorston]

Commit d683c5c2f1 (tr: support octal ranges) broke the previous
behaviour that an escaped dash doesn't indicate a range:
'[p\-r]' should match 'p', '-' or 'r', not 'p', 'q' or 'r'.

Add a special case to handle this.

function                                             old     new   delta
expand                                               641     657     +16
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/0 up/down: 16/0)               Total: 16 bytes

Signed-off-by: Ron Yorston <rmy at pobox.com>
---
 coreutils/tr.c     | 5 +++++
 testsuite/tr.tests | 4 ++++
 2 files changed, 9 insertions(+)

diff --git a/coreutils/tr.c b/coreutils/tr.c
index 8d779d8ea..4d9796f80 100644
--- a/coreutils/tr.c
+++ b/coreutils/tr.c
@@ -117,6 +117,11 @@ static unsigned expand(char *arg, char **buffer_p)
 			arg++;
 			z = arg;
 			ac = bb_process_escape_sequence(&z);
+			if (ac == '\\' && *z == '-') {
+				/* An escaped dash isn't a range, don't fall through */
+				buffer[pos++] = *z;
+				continue;
+			}
 			arg = (char *)z;
 			arg--;
 			*arg = ac;
diff --git a/testsuite/tr.tests b/testsuite/tr.tests
index 5cca299ac..ab198d9f8 100755
--- a/testsuite/tr.tests
+++ b/testsuite/tr.tests
@@ -15,6 +15,10 @@ testing "tr understands 0-9A-F" \
 	"tr -cd '[0-9A-F]'" \
 	"19AF" "" "19AFH\n"
 
+testing "tr does not treat [p\\-r] as a range" \
+	"tr '[p\\-r]' '+'" \
+	"o+q+s+\n" "" "opqrs-\n"
+
 optional FEATURE_TR_CLASSES
 testing "tr understands [:xdigit:]" \
 	"tr -cd '[:xdigit:]'" \
-- 
2.50.1