regcomp.c: Warn on [:^posix:] not being in []

A POSIX character class is has to be in a bracketed character class.  A
warning is issued when something appearing to be one is found outside.
Until this commit the warning wasn't raised for negated classes.

1 files changed, 3 insertions, 0 deletions

diff --git a/regcomp.c b/regcomp.c
index edab543e42..0d6d344970 100644
--- a/regcomp.c
+++ b/regcomp.c
@@ -13864,6 +13864,9 @@ S_regclass(pTHX_ RExC_state_t *pRExC_state, I32 *flagp, U32 depth,
 	const char *s = RExC_parse;
 	const char  c = *s++;
 
+        if (*s == '^') {
+            s++;
+        }
 	while (isWORDCHAR(*s))
 	    s++;
 	if (*s && c == *s && s[1] == ']') {