Fix Perl_av_store off by one error in key comparison

bbrtj · bbrtj · commit 82609a17e5b4 · 2025-12-14T20:48:42.000+01:00
diff --git a/av.c b/av.c
@@ -361,7 +361,7 @@ Perl_av_store(pTHX_ AV *av, SSize_t key, SV *val)
             return NULL;
     }
 
-    if (SvREADONLY(av) && key >= AvFILL(av))
+    if (SvREADONLY(av) && key > AvFILL(av))
         croak_no_modify();
 
     if (!AvREAL(av) && AvREIFY(av))

Original file line number	Diff line number	Diff line change
`@@ -361,7 +361,7 @@ Perl_av_store(pTHX_ AV av, SSize_t key, SV val)`
`361`	`361`	`return NULL;`
`362`	`362`	`}`
`363`	`363`
`364`		`- if (SvREADONLY(av) && key >= AvFILL(av))`
	`364`	`+ if (SvREADONLY(av) && key > AvFILL(av))`
`365`	`365`	`croak_no_modify();`
`366`	`366`
`367`	`367`	`if (!AvREAL(av) && AvREIFY(av))`