grep: -Pz no longer misdiagnoses [^a]

Problem reported by Michael Jess.
* NEWS: Document this.
* src/pcresearch.c (Pcompile): Do not diagnose [^ when [ is unescaped.
* tests/pcre: Test for the bug.

1 files changed, 1 insertions, 0 deletions

diff --git a/tests/pcre b/tests/pcre
index b8b46624..8f3d9a48 100755
--- a/tests/pcre
+++ b/tests/pcre
@@ -15,5 +15,6 @@ fail=0
 echo | grep -P '\s*$' || fail=1
 echo | returns_ 2 grep -zP '\s$' || fail=1
 echo '.ab' | returns_ 1 grep -Pwx ab || fail=1
+echo x | grep -Pz '[^a]' || fail=1
 
 Exit $fail