[PATCH, committed] Fix PR fortran/82884

[Steve Kargl]

Once the bug is found, the fix is obvious.   Briefly,
in a typespec, ts.u.cl and ts.u.pad are in the same
union.  When parsing a Hollerith, ts.u.pad is is set
to a nonzero value.  Later, when resolving the array
constructor with Hollerith entities, a reference to
ts.u.cl is made which is a mangled non-NULL pointer.
The fix is to clear ts.u.pad in the hollerith to 
character conversion function.

Regression tested on x86_64-*-freebsd.

2017-11-08  Steven G. Kargl  <kargl@gcc.gnu.org>

	PR fortran/82884
	* arith.c (gfc_hollerith2character): Clear pad.

2017-11-08  Steven G. Kargl  <kargl@gcc.gnu.org>

	PR fortran/82884
	* gfortran.dg/hollerith_character_array_constructor.f90: New test.

Index: gcc/fortran/arith.c
===================================================================
--- gcc/fortran/arith.c	(revision 254461)
+++ gcc/fortran/arith.c	(working copy)
@@ -2604,6 +2604,7 @@ gfc_hollerith2character (gfc_expr *src, int kind)
   result = gfc_copy_expr (src);
   result->ts.type = BT_CHARACTER;
   result->ts.kind = kind;
+  result->ts.u.pad = 0;
 
   result->value.character.length = result->representation.length;
   result->value.character.string
Index: gcc/testsuite/gfortran.dg/hollerith_character_array_constructor.f90
===================================================================
--- gcc/testsuite/gfortran.dg/hollerith_character_array_constructor.f90	(nonexistent)
+++ gcc/testsuite/gfortran.dg/hollerith_character_array_constructor.f90	(working copy)
@@ -0,0 +1,11 @@
+! { dg-do run }
+! { dg-options "-w" }
+! PR fortran/82884
+! Original code contributed by Gerhard Steinmetz
+program p
+   character :: c(4) = [1h(, 1hi, 1h4, 1h)]
+   if (c(1) /= '(') call abort
+   if (c(2) /= 'i') call abort
+   if (c(3) /= '4') call abort
+   if (c(4) /= ')') call abort
+end

-- 
Steve