From b82d83cdc63017718313fbbc5c692cd9e7b48554 Mon Sep 17 00:00:00 2001
From: Eric Brine <ikegami@adaelis.com>
Date: Tue, 19 Oct 2010 18:34:17 -0700
Subject: [PATCH] Don't warn for splice(@a,MAX_LEN) [RT#78462]

The intent of splice(@a,MAX_LEN) is quite clearly to truncate
the array if it's too large. There's no reason to warn if the
array is currently smaller than the max length.
---
 pod/perldelta.pod |    5 +++++
 pp.c              |    3 ++-
 t/lib/warnings/pp |   13 +++++++++++++
 3 files changed, 20 insertions(+), 1 deletions(-)

diff --git a/pod/perldelta.pod b/pod/perldelta.pod
index 3715fe4..fbe5eaa 100644
--- a/pod/perldelta.pod
+++ b/pod/perldelta.pod
@@ -124,6 +124,11 @@ You can now use the C<keys>, C<values>, C<each> builtin functions on arrays
 This is actually a change introduced in perl 5.12.0, but it was missed from
 that release's perldelta.
 
+=head2 C<splice()> doesn't warn when truncating
+
+You can now limit the size of an array using C<splice(@a,MAX_LEN)> without
+worrying about warnings.
+
 =head1 Security
 
 XXX Any security-related notices go here.  In particular, any security
diff --git a/pp.c b/pp.c
index b777f39..ad0611f 100644
--- a/pp.c
+++ b/pp.c
@@ -5198,7 +5198,8 @@ PP(pp_splice)
 	length = AvMAX(ary) + 1;
     }
     if (offset > AvFILLp(ary) + 1) {
-	Perl_ck_warner(aTHX_ packWARN(WARN_MISC), "splice() offset past end of array" );
+	if (SP - MARK)
+	    Perl_ck_warner(aTHX_ packWARN(WARN_MISC), "splice() offset past end of array" );
 	offset = AvFILLp(ary) + 1;
     }
     after = AvFILLp(ary) + 1 - (offset + length);
diff --git a/t/lib/warnings/pp b/t/lib/warnings/pp
index d158144..838274e 100644
--- a/t/lib/warnings/pp
+++ b/t/lib/warnings/pp
@@ -46,6 +46,19 @@ EXPECT
 Attempt to use reference as lvalue in substr at - line 5.
 ########
 # pp.c
+use warnings 'misc' ;
+@a = qw( a b c );
+splice(@a, 4, 0, 'e') ;
+use warnings 'misc' ;
+@a = qw( a b c );
+splice(@a, 4) ;
+no warnings 'misc' ;
+@a = qw( a b c );
+splice(@a, 4, 0, 'e') ;
+EXPECT
+splice() offset past end of array at - line 4.
+########
+# pp.c
 use warnings 'uninitialized' ;
 *x = *{ undef() };
 no warnings 'uninitialized' ;
-- 
1.7.1.1

From 3893fef7fda5b2563eb64f8a2a6d66d815bf3108 Mon Sep 17 00:00:00 2001
From: Eric Brine <ikegami@adaelis.com>
Date: Wed, 2 Mar 2011 17:30:17 -0500
Subject: [PATCH] The intent of splice(@a,MAX_LEN) is quite clearly to truncate
 the array if it's too large. There's no reason to warn if it's
 currently smaller than the max length.

---
 pod/perldelta.pod |    5 +++++
 pp.c              |    4 +++-
 t/lib/warnings/pp |   19 +++++++++++++++++++
 3 files changed, 27 insertions(+), 1 deletions(-)

diff --git a/pod/perldelta.pod b/pod/perldelta.pod
index 5a020c9..78a6a04 100644
--- a/pod/perldelta.pod
+++ b/pod/perldelta.pod
@@ -27,6 +27,11 @@ L<feature.pm|feature>, even outside the scope of C<use feature>.  Relevant
 documentation files L<CORE>, L<feature>, L<perlfunc>, L<perlsub>, and
 L<perlsyn> have been updated.
 
+=head2 C<splice()> doesn't warn when truncating
+
+You can now limit the size of an array using C<splice(@a,MAX_LEN)> without
+worrying about warnings.
+
 =head2 C<continue> no longer requires the "switch" feature
 
 The C<continue> keyword has two meanings.  It can introduce a C<continue>
diff --git a/pp.c b/pp.c
index 385f1be..d3d4cc8 100644
--- a/pp.c
+++ b/pp.c
@@ -5434,6 +5434,7 @@ S_deref_plain_array(pTHX_ AV *ary)
 PP(pp_splice)
 {
     dVAR; dSP; dMARK; dORIGMARK;
+    int num_args = (SP - MARK);
     register AV *ary = DEREF_PLAIN_ARRAY(MUTABLE_AV(*++MARK));
     register SV **src;
     register SV **dst;
@@ -5477,7 +5478,8 @@ PP(pp_splice)
 	length = AvMAX(ary) + 1;
     }
     if (offset > AvFILLp(ary) + 1) {
-	Perl_ck_warner(aTHX_ packWARN(WARN_MISC), "splice() offset past end of array" );
+	if (num_args > 2)
+	    Perl_ck_warner(aTHX_ packWARN(WARN_MISC), "splice() offset past end of array" );
 	offset = AvFILLp(ary) + 1;
     }
     after = AvFILLp(ary) + 1 - (offset + length);
diff --git a/t/lib/warnings/pp b/t/lib/warnings/pp
index d158144..2251b94 100644
--- a/t/lib/warnings/pp
+++ b/t/lib/warnings/pp
@@ -46,6 +46,25 @@ EXPECT
 Attempt to use reference as lvalue in substr at - line 5.
 ########
 # pp.c
+use warnings 'misc' ;
+@a = qw( a b c );
+splice(@a, 4, 0, 'e') ;
+@a = qw( a b c );
+splice(@a, 4, 1) ;
+@a = qw( a b c );
+splice(@a, 4) ;
+no warnings 'misc' ;
+@a = qw( a b c );
+splice(@a, 4, 0, 'e') ;
+@a = qw( a b c );
+splice(@a, 4, 1) ;
+@a = qw( a b c );
+splice(@a, 4) ;
+EXPECT
+splice() offset past end of array at - line 4.
+splice() offset past end of array at - line 6.
+########
+# pp.c
 use warnings 'uninitialized' ;
 *x = *{ undef() };
 no warnings 'uninitialized' ;
-- 
1.7.2.5