Make PL_(top|body|form)target PVIVs

These are only used for storing a string and an IV.

Making them into full-blown SVt_PVFMs is overkill.

FmLINES was only being used on these three scalars.  So make it use
the SvIVX field.  struct xpvfm no longer needs an xfm_lines member,
because SVt_PVFMs no longer use it.

This also causes a TODO test in taint.t to start passing, but I do
not fully understand why.  But at least that’s progress. :-)

6 files changed, 19 insertions, 15 deletions

diff --git a/dump.c b/dump.c
index 022983d8a9..c7a40a6949 100644
--- a/dump.c
+++ b/dump.c
@@ -1924,8 +1924,6 @@ Perl_do_sv_dump(pTHX_ I32 level, PerlIO *file, SV *sv, I32 nest, I32 maxnest, bo
 	    Perl_dump_indent(aTHX_ level, file, "  DEPTH = %"IVdf"\n", (IV)CvDEPTH(sv));
 	Perl_dump_indent(aTHX_ level, file, "  FLAGS = 0x%"UVxf"\n", (UV)CvFLAGS(sv));
 	Perl_dump_indent(aTHX_ level, file, "  OUTSIDE_SEQ = %"UVuf"\n", (UV)CvOUTSIDE_SEQ(sv));
-	if (type == SVt_PVFM)
-	    Perl_dump_indent(aTHX_ level, file, "  LINES = %"IVdf"\n", (IV)FmLINES(sv));
 	Perl_dump_indent(aTHX_ level, file, "  PADLIST = 0x%"UVxf"\n", PTR2UV(CvPADLIST(sv)));
 	if (nest < maxnest) {
 	    do_dump_pad(level+1, file, CvPADLIST(sv), 0);
diff --git a/ext/B/B.xs b/ext/B/B.xs
index b503611c64..9c9133b9ff 100644
--- a/ext/B/B.xs
+++ b/ext/B/B.xs
@@ -1446,8 +1446,6 @@ MODULE = B	PACKAGE = B::IV
 
 #define PVAV_max_ix	sv_SSize_tp | offsetof(struct xpvav, xav_max)
 
-#define PVFM_lines_ix	sv_IVp | offsetof(struct xpvfm, xfm_lines)
-
 #define PVCV_stash_ix	sv_SVp | offsetof(struct xpvcv, xcv_stash) 
 #define PVCV_gv_ix	sv_SVp | offsetof(struct xpvcv, xcv_gv)
 #define PVCV_file_ix	sv_char_pp | offsetof(struct xpvcv, xcv_file)
@@ -1504,7 +1502,6 @@ IVX(sv)
 	B::IO::IoTYPE = PVIO_type_ix
 	B::IO::IoFLAGS = PVIO_flags_ix
 	B::AV::MAX = PVAV_max_ix
-	B::FM::LINES = PVFM_lines_ix
 	B::CV::STASH = PVCV_stash_ix
 	B::CV::GV = PVCV_gv_ix
 	B::CV::FILE = PVCV_file_ix
@@ -1961,6 +1958,17 @@ AvFLAGS(av)
 
 #endif
 
+MODULE = B	PACKAGE = B::FM		PREFIX = Fm
+
+#if PERL_VERSION > 7 || (PERL_VERSION == 7 && PERL_SUBVERSION >= 3)
+# undef FmLINES
+# define FmLINES(sv) 0
+#endif
+
+IV
+FmLINES(form)
+	B::FM	form
+
 MODULE = B	PACKAGE = B::CV		PREFIX = Cv
 
 U32
diff --git a/mg.c b/mg.c
index 3b4ed1c052..2ac49bff59 100644
--- a/mg.c
+++ b/mg.c
@@ -814,7 +814,8 @@ Perl_magic_get(pTHX_ SV *sv, MAGIC *mg)
 
     switch (*mg->mg_ptr) {
     case '\001':		/* ^A */
-	sv_setsv(sv, PL_bodytarget);
+	if (SvOK(PL_bodytarget)) sv_copypv(sv, PL_bodytarget);
+	else sv_setsv(sv, &PL_sv_undef);
 	if (SvTAINTED(PL_bodytarget))
 	    SvTAINTED_on(sv);
 	break;
@@ -2542,7 +2543,8 @@ Perl_magic_set(pTHX_ SV *sv, MAGIC *mg)
         }
         break;
     case '\001':	/* ^A */
-	sv_setsv(PL_bodytarget, sv);
+	if (SvOK(sv)) sv_copypv(PL_bodytarget, sv);
+	else SvOK_off(PL_bodytarget);
 	FmLINES(PL_bodytarget) = 0;
 	if (SvPOK(PL_bodytarget)) {
 	    char *s = SvPVX(PL_bodytarget);
diff --git a/perl.c b/perl.c
index d8b8aca63e..d836b0b33b 100644
--- a/perl.c
+++ b/perl.c
@@ -4137,9 +4137,9 @@ S_init_postdump_symbols(pTHX_ register int argc, register char **argv, register
 
     PERL_ARGS_ASSERT_INIT_POSTDUMP_SYMBOLS;
 
-    PL_toptarget = newSV_type(SVt_PVFM);
+    PL_toptarget = newSV_type(SVt_PVIV);
     sv_setpvs(PL_toptarget, "");
-    PL_bodytarget = newSV_type(SVt_PVFM);
+    PL_bodytarget = newSV_type(SVt_PVIV);
     sv_setpvs(PL_bodytarget, "");
     PL_formtarget = PL_bodytarget;
 
diff --git a/sv.h b/sv.h
index 056d43b118..b2385d0a6d 100644
--- a/sv.h
+++ b/sv.h
@@ -520,7 +520,6 @@ typedef U16 cv_flags_t;
 struct xpvfm {
     _XPV_HEAD;
     _XPVCV_COMMON;
-    IV		xfm_lines;
 };
 
 
@@ -1387,7 +1386,7 @@ sv_force_normal does nothing.
 
 #endif
 
-#define FmLINES(sv)	((XPVFM*)  SvANY(sv))->xfm_lines
+#define FmLINES(sv)	((XPVIV*)  SvANY(sv))->xiv_iv
 
 #define LvTYPE(sv)	((XPVLV*)  SvANY(sv))->xlv_type
 #define LvTARG(sv)	((XPVLV*)  SvANY(sv))->xlv_targ
diff --git a/t/op/taint.t b/t/op/taint.t
index c8537fce40..0e89c1f87a 100644
--- a/t/op/taint.t
+++ b/t/op/taint.t
@@ -2050,10 +2050,7 @@ end
     formline('@' .('<'*5) . ' | @*', 'hallo', 'welt');
     isnt_tainted($^A, "accumulator still untainted");
     formline('@' .('<'*(5+$TAINT0)) . ' | @*', 'hallo', 'welt');
-    TODO: {
-        local $::TODO = "get magic handled too late?";
-        is_tainted($^A, "the accumulator should be tainted already");
-    }
+    is_tainted($^A, "the accumulator should be tainted already");
     is_tainted($^A, "tainted formline picture makes a tainted accumulator");
 }