From 84807af0ca6dfdb81abb8e925ce32acbcab29868 Mon Sep 17 00:00:00 2001
From: Steve Kargl <kargl@gcc.gnu.org>
Date: Mon, 17 Oct 2022 22:42:40 +0200
Subject: [PATCH] Fortran: NULL pointer dereference in gfc_simplify_image_index
 [PR104330]

gcc/fortran/ChangeLog:

	PR fortran/104330
	* simplify.cc (gfc_simplify_image_index): Do not dereference NULL
	pointer.

gcc/testsuite/ChangeLog:

	PR fortran/104330
	* gfortran.dg/pr104330.f90: New test.
---
 gcc/fortran/simplify.cc                |  2 +-
 gcc/testsuite/gfortran.dg/pr104330.f90 | 20 ++++++++++++++++++++
 2 files changed, 21 insertions(+), 1 deletion(-)
 create mode 100644 gcc/testsuite/gfortran.dg/pr104330.f90

diff --git a/gcc/fortran/simplify.cc b/gcc/fortran/simplify.cc
index 6ac92cf9db8..9c2fea8c5f2 100644
--- a/gcc/fortran/simplify.cc
+++ b/gcc/fortran/simplify.cc
@@ -8266,7 +8266,7 @@ gfc_simplify_image_index (gfc_expr *coarray, gfc_expr *sub)
     if (ref->type == REF_COMPONENT)
       as = ref->u.ar.as;
 
-  if (as->type == AS_DEFERRED)
+  if (!as || as->type == AS_DEFERRED)
     return NULL;
 
   /* "valid sequence of cosubscripts" are required; thus, return 0 unless
diff --git a/gcc/testsuite/gfortran.dg/pr104330.f90 b/gcc/testsuite/gfortran.dg/pr104330.f90
new file mode 100644
index 00000000000..9ff48e2f6cc
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/pr104330.f90
@@ -0,0 +1,20 @@
+! { dg-do compile }
+! { dg-options "-fcoarray=lib" }
+!
+! PR fortran/104330 - ICE in gfc_simplify_image_index
+! Contributed by G.Steinmetz
+
+program p
+  implicit none
+  type t
+  end type t
+  class(*), allocatable :: x[:]
+  class(t), allocatable :: y[:]
+  type(t),  allocatable :: z[:]
+  allocate (real :: x[*])
+  print *, image_index(x, [1])
+  allocate (t :: y[*])
+  print *, image_index(y, [1])
+  allocate (t :: z[*])
+  print *, image_index(z, [1])
+end
-- 
2.35.3