Revert "avoid identical stack traces"

This reverts commit b7b8b099a2106c45a577e9cd7b9f1653736cf89a.

I do not think this is currently suitable for maint, given GH#17567
and the attempt at fixing it in fb8188b84d which was itself
reverted in 6311900a66. (See also the documentation update in
ee428a211d.)

6 files changed, 2 insertions, 63 deletions

diff --git a/MANIFEST b/MANIFEST
index a92fe86f8d..2656e61250 100644
--- a/MANIFEST
+++ b/MANIFEST
@@ -5476,9 +5476,6 @@ t/lib/feature/nonesuch		Tests for enabling/disabling nonexistent feature
 t/lib/feature/removed		Tests for enabling/disabling removed feature
 t/lib/feature/say		Tests for enabling/disabling say feature
 t/lib/feature/switch		Tests for enabling/disabling switch feature
-t/lib/GH_15109/Apack.pm		test Module for caller.t
-t/lib/GH_15109/Bpack.pm		test Module for caller.t
-t/lib/GH_15109/Cpack.pm		test Module for caller.t
 t/lib/h2ph.h			Test header file for h2ph
 t/lib/h2ph.pht			Generated output from h2ph.h by h2ph, for comparison
 t/lib/locale/latin1		Part of locale.t in Latin 1
diff --git a/op.c b/op.c
index cd57762b2f..60b3627575 100644
--- a/op.c
+++ b/op.c
@@ -10460,32 +10460,10 @@ S_process_special_blocks(pTHX_ I32 floor, const char *const fullname,
             (void)CvGV(cv);
 	    if (floor) LEAVE_SCOPE(floor);
 	    ENTER;
-
-            SAVEVPTR(PL_curcop);
-            if (PL_curcop == &PL_compiling) {
-                /* Avoid pushing the "global" &PL_compiling onto the
-                 * context stack. For example, a stack trace inside
-                 * nested use's would show all calls coming from whoever
-                 * most recently updated PL_compiling.cop_file and
-                 * cop_line.  So instead, temporarily set PL_curcop to a
-                 * private copy of &PL_compiling. PL_curcop will soon be
-                 * set to point back to &PL_compiling anyway but only
-                 * after the temp value has been pushed onto the context
-                 * stack as blk_oldcop.
-                 * This is slightly hacky, but necessary. Note also
-                 * that in the brief window before PL_curcop is set back
-                 * to PL_compiling, IN_PERL_COMPILETIME/IN_PERL_RUNTIME
-                 * will give the wrong answer.
-                 */
-                Newx(PL_curcop, 1, COP);
-                StructCopy(&PL_compiling, PL_curcop, COP);
-                PL_curcop->op_slabbed = 0;
-                SAVEFREEPV(PL_curcop);
-            }
-
             PUSHSTACKi(PERLSI_REQUIRE);
 	    SAVECOPFILE(&PL_compiling);
 	    SAVECOPLINE(&PL_compiling);
+	    SAVEVPTR(PL_curcop);
 
 	    DEBUG_x( dump_sub(gv) );
 	    Perl_av_create_and_push(aTHX_ &PL_beginav, MUTABLE_SV(cv));
diff --git a/t/lib/GH_15109/Apack.pm b/t/lib/GH_15109/Apack.pm
deleted file mode 100644
index fa52ec8b53..0000000000
--- a/t/lib/GH_15109/Apack.pm
+++ /dev/null
@@ -1,4 +0,0 @@
-# for use by caller.t for GH #15109
-package Apack;
-use Bpack;
-1;
diff --git a/t/lib/GH_15109/Bpack.pm b/t/lib/GH_15109/Bpack.pm
deleted file mode 100644
index f9421c813f..0000000000
--- a/t/lib/GH_15109/Bpack.pm
+++ /dev/null
@@ -1,4 +0,0 @@
-# for use by caller.t for GH #15109
-package Bpack;
-use Cpack;
-1;
diff --git a/t/lib/GH_15109/Cpack.pm b/t/lib/GH_15109/Cpack.pm
deleted file mode 100644
index 94c409b05c..0000000000
--- a/t/lib/GH_15109/Cpack.pm
+++ /dev/null
@@ -1,11 +0,0 @@
-# for use by caller.t for GH #15109
-package Cpack;
-
-
-my $i = 0;
-
-while (my ($package, $file, $line) = caller($i++)) {
-    push @Cpack::callers, "$file:$line";
-}
-
-1;
diff --git a/t/op/caller.t b/t/op/caller.t
index 9fc9a1ce39..564d140cc0 100644
--- a/t/op/caller.t
+++ b/t/op/caller.t
@@ -5,7 +5,7 @@ BEGIN {
     chdir 't' if -d 't';
     require './test.pl';
     set_up_inc('../lib');
-    plan( tests => 109 ); # some tests are run in a BEGIN block
+    plan( tests => 97 ); # some tests are run in a BEGIN block
 }
 
 my @c;
@@ -335,22 +335,6 @@ $::testing_caller = 1;
 
 do './op/caller.pl' or die $@;
 
-# GH #15109
-# See that callers within a nested series of 'use's gets the right
-# filenames.
-{
-    local @INC = 'lib/GH_15109/';
-    # Apack use's Bpack which use's Cpack which populates @Cpack::caller
-    # with the file:N of all the callers
-    eval 'use Apack; 1';
-    is($@, "", "GH #15109 - eval");
-    is (scalar(@Cpack::callers), 10, "GH #15109 - callers count");
-    like($Cpack::callers[$_], qr{GH_15109/Bpack.pm:3}, "GH #15109 level $_") for 0..2;
-    like($Cpack::callers[$_], qr{GH_15109/Apack.pm:3}, "GH #15109 level $_") for 3..5;
-    like($Cpack::callers[$_], qr{\(eval \d+\):1}, "GH #15109 level $_") for 6..8;
-    like($Cpack::callers[$_], qr{caller\.t}, "GH #15109 level $_") for 9;
-}
-
 {
     package RT129239;
     BEGIN {
@@ -364,4 +348,3 @@ do './op/caller.pl' or die $@;
 #line 12345 "virtually/op/caller.t"
     }
 }
-