Negative subscripts optionally passed to tied array methods

Message-id: <20020415033855.6343.qmail@plover.com>

p4raw-id: //depot/perl@17727

1 files changed, 131 insertions, 50 deletions

diff --git a/av.c b/av.c
index 3146f25635..a1d62fbdcb 100644
--- a/av.c
+++ b/av.c
@@ -184,23 +184,42 @@ Perl_av_fetch(pTHX_ register AV *av, I32 key, I32 lval)
     if (!av)
 	return 0;
 
+    if (SvRMAGICAL(av)) {
+        MAGIC *tied_magic = mg_find((SV*)av, PERL_MAGIC_tied);
+        if (tied_magic || mg_find((SV*)av, PERL_MAGIC_regdata)) {
+            U32 adjust_index = 1;
+
+            if (tied_magic && key < 0) {
+                /* Handle negative array indices 20020222 MJD */
+                SV **negative_indices_glob = 
+                    hv_fetch(SvSTASH(SvRV(SvTIED_obj((SV *)av, 
+                                                     tied_magic))), 
+                             NEGATIVE_INDICES_VAR, 16, 0);
+
+                if (negative_indices_glob
+                    && SvTRUE(GvSV(*negative_indices_glob)))
+                    adjust_index = 0;
+            }
+
+            if (key < 0 && adjust_index) {
+                key += AvFILL(av) + 1;
+                if (key < 0)
+                    return 0;
+            }
+
+            sv = sv_newmortal();
+            mg_copy((SV*)av, sv, 0, key);
+            PL_av_fetch_sv = sv;
+            return &PL_av_fetch_sv;
+        }
+    }
+
     if (key < 0) {
 	key += AvFILL(av) + 1;
 	if (key < 0)
 	    return 0;
     }
 
-    if (SvRMAGICAL(av)) {
-	if (mg_find((SV*)av, PERL_MAGIC_tied) ||
-		mg_find((SV*)av, PERL_MAGIC_regdata))
-	{
-	    sv = sv_newmortal();
-	    mg_copy((SV*)av, sv, 0, key);
-	    PL_av_fetch_sv = sv;
-	    return &PL_av_fetch_sv;
-	}
-    }
-
     if (key > AvFILLp(av)) {
 	if (!lval)
 	    return 0;
@@ -251,6 +270,33 @@ Perl_av_store(pTHX_ register AV *av, I32 key, SV *val)
     if (!val)
 	val = &PL_sv_undef;
 
+    if (SvRMAGICAL(av)) {
+        MAGIC *tied_magic = mg_find((SV*)av, PERL_MAGIC_tied);
+        if (tied_magic) {
+            /* Handle negative array indices 20020222 MJD */
+            if (key < 0) {
+                unsigned adjust_index = 1;
+                SV **negative_indices_glob = 
+                    hv_fetch(SvSTASH(SvRV(SvTIED_obj((SV *)av, 
+                                                     tied_magic))), 
+                             NEGATIVE_INDICES_VAR, 16, 0);
+                if (negative_indices_glob
+                    && SvTRUE(GvSV(*negative_indices_glob)))
+                    adjust_index = 0;
+                if (adjust_index) {
+                    key += AvFILL(av) + 1;
+                    if (key < 0)
+                        return 0;
+                }
+            }
+	    if (val != &PL_sv_undef) {
+		mg_copy((SV*)av, val, 0, key);
+	    }
+	    return 0;
+        }
+    }
+
+
     if (key < 0) {
 	key += AvFILL(av) + 1;
 	if (key < 0)
@@ -260,15 +306,6 @@ Perl_av_store(pTHX_ register AV *av, I32 key, SV *val)
     if (SvREADONLY(av) && key >= AvFILL(av))
 	Perl_croak(aTHX_ PL_no_modify);
 
-    if (SvRMAGICAL(av)) {
-	if (mg_find((SV*)av, PERL_MAGIC_tied)) {
-	    if (val != &PL_sv_undef) {
-		mg_copy((SV*)av, val, 0, key);
-	    }
-	    return 0;
-	}
-    }
-
     if (!AvREAL(av) && AvREIFY(av))
 	av_reify(av);
     if (key > AvMAX(av))
@@ -750,26 +787,48 @@ Perl_av_delete(pTHX_ AV *av, I32 key, I32 flags)
 	return Nullsv;
     if (SvREADONLY(av))
 	Perl_croak(aTHX_ PL_no_modify);
+
+    if (SvRMAGICAL(av)) {
+        MAGIC *tied_magic = mg_find((SV*)av, PERL_MAGIC_tied);
+        SV **svp;
+        if ((tied_magic || mg_find((SV*)av, PERL_MAGIC_regdata))) {
+            /* Handle negative array indices 20020222 MJD */
+            if (key < 0) {
+                unsigned adjust_index = 1;
+                if (tied_magic) {
+                    SV **negative_indices_glob = 
+                        hv_fetch(SvSTASH(SvRV(SvTIED_obj((SV *)av, 
+                                                         tied_magic))), 
+                                 NEGATIVE_INDICES_VAR, 16, 0);
+                    if (negative_indices_glob
+                        && SvTRUE(GvSV(*negative_indices_glob)))
+                        adjust_index = 0;
+                }
+                if (adjust_index) {
+                    key += AvFILL(av) + 1;
+                    if (key < 0)
+                        return Nullsv;
+                }
+            }
+            svp = av_fetch(av, key, TRUE);
+            if (svp) {
+                sv = *svp;
+                mg_clear(sv);
+                if (mg_find(sv, PERL_MAGIC_tiedelem)) {
+                    sv_unmagic(sv, PERL_MAGIC_tiedelem); /* No longer an element */
+                    return sv;
+                }
+                return Nullsv;     
+            }
+        }
+    }
+
     if (key < 0) {
 	key += AvFILL(av) + 1;
 	if (key < 0)
 	    return Nullsv;
     }
-    if (SvRMAGICAL(av)) {
-	SV **svp;
-	if ((mg_find((SV*)av, PERL_MAGIC_tied) ||
-		mg_find((SV*)av, PERL_MAGIC_regdata))
-	    && (svp = av_fetch(av, key, TRUE)))
-	{
-	    sv = *svp;
-	    mg_clear(sv);
-	    if (mg_find(sv, PERL_MAGIC_tiedelem)) {
-		sv_unmagic(sv, PERL_MAGIC_tiedelem);	/* No longer an element */
-		return sv;
-	    }
-	    return Nullsv;			/* element cannot be deleted */
-	}
-    }
+
     if (key > AvFILLp(av))
 	return Nullsv;
     else {
@@ -807,26 +866,48 @@ Perl_av_exists(pTHX_ AV *av, I32 key)
 {
     if (!av)
 	return FALSE;
+
+
+    if (SvRMAGICAL(av)) {
+        MAGIC *tied_magic = mg_find((SV*)av, PERL_MAGIC_tied);
+        if (tied_magic || mg_find((SV*)av, PERL_MAGIC_regdata)) {
+            SV *sv = sv_newmortal();
+            MAGIC *mg;
+            /* Handle negative array indices 20020222 MJD */
+            if (key < 0) {
+                unsigned adjust_index = 1;
+                if (tied_magic) {
+                    SV **negative_indices_glob = 
+                        hv_fetch(SvSTASH(SvRV(SvTIED_obj((SV *)av, 
+                                                         tied_magic))), 
+                                 NEGATIVE_INDICES_VAR, 16, 0);
+                    if (negative_indices_glob
+                        && SvTRUE(GvSV(*negative_indices_glob)))
+                        adjust_index = 0;
+                }
+                if (adjust_index) {
+                    key += AvFILL(av) + 1;
+                    if (key < 0)
+                        return FALSE;
+                }
+            }
+
+            mg_copy((SV*)av, sv, 0, key);
+            mg = mg_find(sv, PERL_MAGIC_tiedelem);
+            if (mg) {
+                magic_existspack(sv, mg);
+                return (bool)SvTRUE(sv);
+            }
+
+        }
+    }
+
     if (key < 0) {
 	key += AvFILL(av) + 1;
 	if (key < 0)
 	    return FALSE;
     }
-    if (SvRMAGICAL(av)) {
-	if (mg_find((SV*)av, PERL_MAGIC_tied) ||
-		mg_find((SV*)av, PERL_MAGIC_regdata))
-	{
-	    SV *sv = sv_newmortal();
-	    MAGIC *mg;
-
-	    mg_copy((SV*)av, sv, 0, key);
-	    mg = mg_find(sv, PERL_MAGIC_tiedelem);
-	    if (mg) {
-		magic_existspack(sv, mg);
-		return (bool)SvTRUE(sv);
-	    }
-	}
-    }
+
     if (key <= AvFILLp(av) && AvARRAY(av)[key] != &PL_sv_undef
 	&& AvARRAY(av)[key])
     {