Fix checks for tainted dir in $ENV{PATH}

$ cat > foo
#!/usr/bin/perl
print "What?!\n"
^D
$ chmod +x foo
$ ./perl -Ilib -Te '$ENV{PATH}="."; exec "foo"'
Insecure directory in $ENV{PATH} while running with -T switch at -e line 1.

That is what I expect to see.  But:

$ ./perl -Ilib -Te '$ENV{PATH}="/\\:."; exec "foo"'
What?!

Perl is allowing the \ to escape the :, but the \ is not treated as an
escape by the system, allowing a relative path in PATH to be consid-
ered safe.

1 files changed, 1 insertions, 1 deletions

diff --git a/mg.c b/mg.c
index 874933f6ff..8b182e6f24 100644
--- a/mg.c
+++ b/mg.c
@@ -1217,7 +1217,7 @@ Perl_magic_setenv(pTHX_ SV *sv, MAGIC *mg)
 #else
 		const char path_sep = ':';
 #endif
-		s = delimcpy(tmpbuf, tmpbuf + sizeof tmpbuf,
+		s = delimcpy_no_escape(tmpbuf, tmpbuf + sizeof tmpbuf,
 			     s, strend, path_sep, &i);
 		s++;
 		if (i >= (I32)sizeof tmpbuf   /* too long -- assume the worst */