bug#17116: perl mode vs. /./

[Stefan Monnier <monnier@iro.umontreal.ca>]

> $ cat o.pl
> print for /./; #why is the rest of this line in this color?
> $ emacs o.pl

Thanks for the clear test case.

Because perl-mode doesn't understand this code.  It considers the first
slash as a "plain slash" (e.g. the one used for division), whereas the
second, being right after a punctuation (and hence can's be a division),
is assumed to start a regexp.

I installed the patch below which should fix those problems.


        Stefan


=== modified file 'lisp/progmodes/perl-mode.el'
--- lisp/progmodes/perl-mode.el	2014-04-02 19:47:50 +0000
+++ lisp/progmodes/perl-mode.el	2014-04-02 19:48:21 +0000
@@ -276,7 +276,7 @@
       ;; perl-font-lock-special-syntactic-constructs.
       ((concat "\\(?:\\(?:^\\|[^$@&%[:word:]]\\)"
                (regexp-opt '("split" "if" "unless" "until" "while" "split"
-                             "grep" "map" "not" "or" "and"))
+                             "grep" "map" "not" "or" "and" "for" "foreach"))
                "\\|[?:.,;=!~({[]\\|\\(^\\)\\)[ \t\n]*\\(/\\)")
        (2 (ignore
            (if (and (match-end 1)       ; / at BOL.