[perl #6665] Different behavior using the -Idir option on the command line and inside a perl script

Adds the -Idir at the beginning of @INC.

(Plus a test by rgs -- check that -I does not add directories at the end
of the @INC array anymore)

2 files changed, 7 insertions, 5 deletions

diff --git a/perl.c b/perl.c
index 021f35d327..deb9d383b2 100644
--- a/perl.c
+++ b/perl.c
@@ -4873,7 +4873,8 @@ S_incpush_if_exists(pTHX_ SV *dir)
 
     if (PerlLIO_stat(SvPVX_const(dir), &tmpstatbuf) >= 0 &&
 	S_ISDIR(tmpstatbuf.st_mode)) {
-	av_push(GvAVn(PL_incgv), dir);
+	av_unshift( GvAVn( PL_incgv ), 1 );
+	av_store( GvAVn( PL_incgv ), 0, dir );
 	dir = newSV(0);
     }
     return dir;
@@ -5093,8 +5094,9 @@ S_incpush(pTHX_ const char *dir, bool addsubdirs, bool addoldvers, bool usesep,
 #endif
 	}
 
-	/* finally push this lib directory on the end of @INC */
-	av_push(GvAVn(PL_incgv), libdir);
+	/* finally add this lib directory at the beginning of @INC */
+	av_unshift( GvAVn( PL_incgv ), 1 );
+	av_store( GvAVn( PL_incgv ), 0, libdir );
     }
     if (subdir) {
 	assert (SvREFCNT(subdir) == 1);
diff --git a/t/run/switchI.t b/t/run/switchI.t
index 41192cd765..cfb0f6e949 100644
--- a/t/run/switchI.t
+++ b/t/run/switchI.t
@@ -15,11 +15,11 @@ my $Is_VMS   = $^O eq 'VMS';
 my $lib;
 
 $lib = $Is_MacOS ? ':Bla:' : 'Bla';
-ok(grep { $_ eq $lib } @INC);
+ok(grep { $_ eq $lib } @INC[0..($#INC-1)]);
 SKIP: {
   skip 'Double colons not allowed in dir spec', 1 if $Is_VMS;
   $lib = $Is_MacOS ? 'Foo::Bar:' : 'Foo::Bar';
-  ok(grep { $_ eq $lib } @INC);
+  ok(grep { $_ eq $lib } @INC[0..($#INC-1)]);
 }
 
 $lib = $Is_MacOS ? ':Bla2:' : 'Bla2';