Include the name of the non-lvalue sub in error message

This makes the cause of the error more obvious if you accidentally call
a non-lvalue sub in the final position of an lvalue one.

1 files changed, 11 insertions, 3 deletions

diff --git a/op.c b/op.c
index 0d04858b5d..0c2af88c64 100644
--- a/op.c
+++ b/op.c
@@ -2792,6 +2792,7 @@ Perl_op_lvalue_flags(pTHX_ OP *o, I32 type, U32 flags)
 		OP *kid = cUNOPo->op_first;
 		CV *cv;
 		GV *gv;
+                SV *namesv;
 
 		if (kid->op_type != OP_PUSHMARK) {
 		    if (kid->op_type != OP_NULL || kid->op_targ != OP_LIST)
@@ -2829,6 +2830,15 @@ Perl_op_lvalue_flags(pTHX_ OP *o, I32 type, U32 flags)
 		    break;
 		if (CvLVALUE(cv))
 		    break;
+                if (flags & OP_LVALUE_NO_CROAK)
+                    return NULL;
+
+                namesv = cv_name(cv, NULL, 0);
+                yyerror_pv(Perl_form(aTHX_ "Can't modify non-lvalue "
+                                     "subroutine call of &%"SVf" in %s",
+                                     SVfARG(namesv), PL_op_desc[type]),
+                           SvUTF8(namesv));
+                return o;
 	    }
 	}
 	/* FALLTHROUGH */
@@ -2842,9 +2852,7 @@ Perl_op_lvalue_flags(pTHX_ OP *o, I32 type, U32 flags)
 	yyerror(Perl_form(aTHX_ "Can't modify %s in %s",
 		     (o->op_type == OP_NULL && (o->op_flags & OPf_SPECIAL)
 		      ? "do block"
-		      : (o->op_type == OP_ENTERSUB
-			? "non-lvalue subroutine call"
-			: OP_DESC(o))),
+		      : OP_DESC(o)),
 		     type ? PL_op_desc[type] : "local"));
 	return o;