Subject: perl-mode and cperl-mode: Recognize regex after "return"

From: [email-masked] (Harald Jörg)
Date: Mon, 16 Nov 2020 23:13:16 +0100

merge 26850 26745
thanks

I don't know whether I have the authority to merge bugs, but they
clearly are the same issue, so I'll just give it a try.

The apostrophe, as mentioned in the subject of Bug#26850, is irrelevant:
The actual problem in both reports is the failure to recognize a regular
expression after the keyword "return".  The apostrophe just changes the
interpretation of the text which follows.

There are several workarounds: You could, for example, explicitly write
the regexes as $_ =~ /.../; ... but of course, why would you do that,
since $_ is superfluous.  Alternatively, you could just omit the
"return", which is also superfluous in the examples provided.

Nevertheless, the patch fixes the issue, which happens in both perl-mode
and cperl-mode.  I guess that in neither mode the list of keywords which
precede a regex is actually complete, but "return" is a use case
relevant enough to be fixed.
--
Cheers,
haj
>From bab7a88cb14d9b464f2d976094f46eae46500c0c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Harald=20J=C3=B6rg?= <[email-masked]>
Date: Mon, 16 Nov 2020 22:47:31 +0100
Subject: [PATCH] ; cperl-mode, perl-mode: Recognize a regular expression after
 "return"

* lisp/progmodes/perl-mode.el (defconst): Add "return" to
'perl--syntax-exp-intro-keywords' (Bug#26850).

* lisp/progmodes/cperl-mode.el (cperl-find-pods-heres): Add
"return" to the keywords which start a regex.

* test/lisp/progmodes/cperl-mode-tests.el (cperl-test-bug-28650):
New test.
---
 lisp/progmodes/cperl-mode.el                     |  2 +-
 lisp/progmodes/perl-mode.el                      |  2 +-
 .../cperl-mode-resources/cperl-bug-26850.pl      | 16 ++++++++++++++++
 test/lisp/progmodes/cperl-mode-tests.el          | 15 +++++++++++++++
 4 files changed, 33 insertions(+), 2 deletions(-)
 create mode 100644 test/lisp/progmodes/cperl-mode-resources/cperl-bug-26850.pl

diff --git a/lisp/progmodes/cperl-mode.el b/lisp/progmodes/cperl-mode.el
index a42ace105a..0dc45515d4 100644
--- a/lisp/progmodes/cperl-mode.el
+++ b/lisp/progmodes/cperl-mode.el
@@ -3959,7 +3959,7 @@ cperl-find-pods-heres
 					      (not (memq (preceding-char)
 							 '(?$ ?@ ?& ?%)))
 					      (looking-at
-					       "\\(while\\|if\\|unless\\|until\\|and\\|or\\|not\\|xor\\|split\\|grep\\|map\\|print\\|say\\)\\>")))))
+					       "\\(while\\|if\\|unless\\|until\\|and\\|or\\|not\\|xor\\|split\\|grep\\|map\\|print\\|say\\|return\\)\\>")))))
 				    (and (eq (preceding-char) ?.)
 					 (eq (char-after (- (point) 2)) ?.))
 				    (bobp))
diff --git a/lisp/progmodes/perl-mode.el b/lisp/progmodes/perl-mode.el
index 7265aeee45..bb19436cda 100644
--- a/lisp/progmodes/perl-mode.el
+++ b/lisp/progmodes/perl-mode.el
@@ -209,7 +209,7 @@ perl-quote-like-pairs
 (eval-and-compile
   (defconst perl--syntax-exp-intro-keywords
     '("split" "if" "unless" "until" "while" "print"
-      "grep" "map" "not" "or" "and" "for" "foreach"))
+      "grep" "map" "not" "or" "and" "for" "foreach" "return"))
 
   (defconst perl--syntax-exp-intro-regexp
     (concat "\\(?:\\(?:^\\|[^$@&%[:word:]]\\)"
diff --git a/test/lisp/progmodes/cperl-mode-resources/cperl-bug-26850.pl b/test/lisp/progmodes/cperl-mode-resources/cperl-bug-26850.pl
new file mode 100644
index 0000000000..a02ea29fe9
--- /dev/null
+++ b/test/lisp/progmodes/cperl-mode-resources/cperl-bug-26850.pl
@@ -0,0 +1,16 @@
+sub interesting {
+    $_ = shift;
+    return
+         />Today is .+\'s birthday\.</
+      || / like[ds]? your post in </
+      || /like[ds] your new subscription\. </
+      || / likes? that you're interested in </
+      || /> likes? your comment: /
+      || /&amp;birthdays=.*birthdays?\.<\/a>/;
+}
+
+sub boring {
+    return
+         / likes? your post in </
+      || / likes? that you're interested in </
+}
diff --git a/test/lisp/progmodes/cperl-mode-tests.el b/test/lisp/progmodes/cperl-mode-tests.el
index a0dd391840..896160bb88 100644
--- a/test/lisp/progmodes/cperl-mode-tests.el
+++ b/test/lisp/progmodes/cperl-mode-tests.el
@@ -228,6 +228,21 @@ cperl-test-bug-19709
      (cperl-indent-command)
      (forward-line 1))))
 
+(ert-deftest cperl-test-bug-28650 ()
+  "Verify that regular expressions are recognized after 'return'.
+The test uses the syntax property \"inside a string\" for the
+text in regular expressions, which is non-nil for both cperl-mode
+and perl-mode."
+  (with-temp-buffer
+    (insert-file-contents (ert-resource-file "cperl-bug-26850.pl"))
+    (goto-char (point-min))
+    (re-search-forward "sub interesting {[^}]*}")
+    (should-not (equal (nth 3 (cperl-test-ppss (match-string 0) "Today"))
+                       nil))
+    (re-search-forward "sub boring {[^}]*}")
+    (should-not (equal (nth 3 (cperl-test-ppss (match-string 0) "likes\\?"))
+                       nil))))
+
 (ert-deftest cperl-test-bug-30393 ()
   "Verify that indentation is not disturbed by an open paren in col 0.
 Perl is not Lisp: An open paren in column 0 does not start a function."
-- 
2.20.1