From 03fcc0c44bc7972f2c92736daae5b63d601b7c49 Mon Sep 17 00:00:00 2001
From: Dan Collins <dcollinsn@gmail.com>
Date: Fri, 23 Sep 2016 01:21:20 -0400
Subject: [PATCH] [rt #129336] #!perl -i u erroneously interpreted as -u
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Ported to 5.24.0:

commit f54cfdacff1f3744ef08fc70f1f3bc6c7d862e83
Author: Dan Collins <dcollinsn@gmail.com>
Date:   Fri Sep 23 01:21:20 2016 -0400

    [rt #129336] #!perl -i u erroneously interpreted as -u

    Perl_moreswitches processes a single switch, and returns a pointer
    to the start of the next switch. It can return either
    the a pointer to the next flag itself:

        #!perl -n -p
                   ^ Can point here

    Or, to the space before the next "arg":

        #!perl -n -p
                 ^ Can point here

    (Where the next call to Perl_moreswitches will consume " -".)

    In the case of -i[extension], the pointer is by default pointing at
    the space after the end of the argument. The current code tries to
    do the former, by unconditionally advancing the pointer, and then
    advancing it again if it is on a '-'. But that is incorrect:

        #!perl -i p
                  ^ Will point here, but that isn't a flag

    I could fix this by removing the unconditional s++, and having it
    increment by 2 if *(s+1)=='-', but this work isn't actually
    necessary - it's better to just leave it pointing at the space after
    the argument.

Signed-off-by: Petr Písař <ppisar@redhat.com>
---
 perl.c     | 5 -----
 t/op/lex.t | 9 ++++++++-
 2 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/perl.c b/perl.c
index 228a0d8..5cc7d0b 100644
--- a/perl.c
+++ b/perl.c
@@ -3306,11 +3306,6 @@ Perl_moreswitches(pTHX_ const char *s)
 
 	    PL_inplace = savepvn(start, s - start);
 	}
-	if (*s) {
-	    ++s;
-	    if (*s == '-')	/* Additional switches on #! line. */
-		s++;
-	}
 	return s;
     case 'I':	/* -I handled both here and in parse_body() */
 	forbid_setid('I', FALSE);
diff --git a/t/op/lex.t b/t/op/lex.t
index c515449..9ada592 100644
--- a/t/op/lex.t
+++ b/t/op/lex.t
@@ -7,7 +7,7 @@ use warnings;
 
 BEGIN { chdir 't' if -d 't'; require './test.pl'; }
 
-plan(tests => 26);
+plan(tests => 27);
 
 {
     no warnings 'deprecated';
@@ -209,3 +209,10 @@ fresh_perl_is(
    { stderr => 1 },
   's;@{<<a; [perl #123995]'
 );
+
+fresh_perl_like(
+    "#!perl -i u\nprint 'OK'",
+    qr/OK/,
+    {},
+    '[perl #129336] - #!perl -i argument handling'
+);
-- 
2.7.4