Subject: bug#17174: closed (Re: bug#17174: 24.3; perl-mode highlight: unrecognized perl var $' starts a string)

From: [email-masked] (GNU bug Tracking System)
Date: Thu, 03 Apr 2014 00:43:04 +0000

Your bug report

#17174: 24.3; perl-mode highlight: unrecognized perl var $' starts a string

which was filed against the emacs package, has been closed.

The explanation is attached below, along with your original report.
If you require more details, please reply to [email-masked].

-- 
17174: http://debbugs.gnu.org/cgi/bugreport.cgi?bug=17174
GNU Bug Tracking System
Contact [email-masked] with problems

Subject: Re: bug#17174: 24.3; perl-mode highlight: unrecognized perl var $' starts a string
From: Stefan Monnier <[email-masked]>
To: "G.raud" <[email-masked]>
Cc: [email-masked]
Date: Wed, 02 Apr 2014 20:42:46 -0400
List-Id: <debbugs-submit.debbugs.gnu.org>

> $ cat <<"EOF" >test.pl
> #!/usr/bin/perl
> $_ = 'truc'; /ru/;
> print "$'\n"; # this is highlighted as expected
> print $'; # this starts a string that continues to the next line
> print "\n";
> EOF
> $ emacs24 -Q test.pl

Thanks for the clear test case.  I installed the patch below in
emacs-24, which should fix it.

        Stefan

--- lisp/progmodes/perl-mode.el	2014-04-02 19:50:05 +0000
+++ lisp/progmodes/perl-mode.el	2014-04-03 00:37:11 +0000
@@ -250,7 +250,11 @@
       ;; Catch ${ so that ${var} doesn't screw up indentation.
       ;; This also catches $' to handle 'foo$', although it should really
       ;; check that it occurs inside a '..' string.
-      ("\\(\\$\\)[{']" (1 ". p"))
+      ("\\(\\$\\)[{']" (1 (unless (and (eq ?\' (char-after (match-end 1)))
+                                       (save-excursion
+                                         (not (nth 3 (syntax-ppss
+                                                      (match-beginning 0))))))
+                            (string-to-syntax ". p"))))
       ;; Handle funny names like $DB'stop.
       ("\\$ ?{?^?[_[:alpha:]][_[:alnum:]]*\\('\\)[_[:alpha:]]" (1 "_"))
       ;; format statements

Subject: 24.3; perl-mode highlight: unrecognized perl var $' starts a string
From: "G.raud" <[email-masked]>
To: [email-masked]
Date: Wed, 2 Apr 2014 14:14:11 +0200
List-Id: <debbugs-submit.debbugs.gnu.org>

The bug is an old one, found in Emacs 22, 23 and 24 in Debian.

To test:

$ cat <<"EOF" >test.pl
#!/usr/bin/perl
$_ = 'truc'; /ru/;
print "$'\n"; # this is highlighted as expected
print $'; # this starts a string that continues to the next line
print "\n";
EOF
$ emacs24 -Q test.pl

The output of (report-bug-emacs) follows.

---

In GNU Emacs 24.3.1 (x86_64-pc-linux-gnu, GTK+ Version 3.8.6)
 of 2013-12-22 on brahms, modified by Debian
Windowing system distributor `The X.Org Foundation', version 11.0.11204000
Configured using:
 `configure '--build' 'x86_64-linux-gnu' '--build' 'x86_64-linux-gnu'
 '--prefix=/usr' '--sharedstatedir=/var/lib' '--libexecdir=/usr/lib'
 '--localstatedir=/var/lib' '--infodir=/usr/share/info'
 '--mandir=/usr/share/man' '--with-pop=yes'
 '--enable-locallisppath=/etc/emacs24:/etc/emacs:/usr/local/share/emacs/24.3/site-lisp:/usr/local/share/emacs/site-lisp:/usr/share/emacs/24.3/site-lisp:/usr/share/emacs/site-lisp'
 '--with-crt-dir=/usr/lib/x86_64-linux-gnu' '--with-x=yes'
 '--with-x-toolkit=gtk3' '--with-toolkit-scroll-bars'
 'build_alias=x86_64-linux-gnu' 'CFLAGS=-g -O2 -fstack-protector
 --param=ssp-buffer-size=4 -Wformat -Werror=format-security -Wall'
 'LDFLAGS=-Wl,-z,relro' 'CPPFLAGS=-D_FORTIFY_SOURCE=2''

Important settings:
  value of $LANG: de_DE.UTF-8
  locale-coding-system: utf-8-unix
  default enable-multibyte-characters: t

Major mode: Perl

Minor modes in effect:
  tooltip-mode: t
  mouse-wheel-mode: t
  tool-bar-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  blink-cursor-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  line-number-mode: t
  transient-mark-mode: t

Recent input:
M-x r e p o r t <tab> <return>

Recent messages:
For information about GNU Emacs and the GNU system, type C-h C-a.
user-error: Beginning of history; no preceding item
user-error: End of history; no default available
(New file)
Mark set
byte-code: End of buffer [2 times]

Load-path shadows:
None found.

Features:
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