[perl #119799] Set breakpoints without *DB::dbline

The elements of the %{"_<..."} hashes (where ‘...’ is the filename),
whose keys are line numbers, are used to set breakpoints on the given
lines.  The corresponding @{"_<..."} array contains the actual lines
of source code.

%{"_<..."} actually acts on the array of lines that @DB::dbline is
aliased to.  The assumption is that *DB::dbline = *{"_<..."} will have
taken place first.  Hence, all %{"_<..."} hashes are the same, when it
comes to writing to keys.

It is more useful for each %{"_<..."} hash to set breakpoints on its
corresponding file’s lines regardless of whether @DB::dbline has been
aliased, so that is what this commit does.

Each hash’s mg_obj pointer in its dbfile magic now points to the
array, and magic_setdbline uses it instead of PL_DBline.

1 files changed, 1 insertions, 1 deletions

diff --git a/gv.c b/gv.c
index c7453156ce..e7ef9a7ec4 100644
--- a/gv.c
+++ b/gv.c
@@ -132,7 +132,7 @@ Perl_gv_fetchfile_flags(pTHX_ const char *const name, const STRLEN namelen,
 #endif
     }
     if ((PERLDB_LINE || PERLDB_SAVESRC) && !GvAV(gv))
-	    hv_magic(GvHVn(gv_AVadd(gv)), NULL, PERL_MAGIC_dbfile);
+	    hv_magic(GvHVn(gv), GvAVn(gv), PERL_MAGIC_dbfile);
     if (tmpbuf != smallbuf)
 	Safefree(tmpbuf);
     return gv;