diff --git a/gcc/fortran/ChangeLog b/gcc/fortran/ChangeLog
index ad04007c119f9e5d263ca8902371c3353a6219c0..c79242d9dd5cce9d31a4ef1e743be79fb6b1cb8e 100644
--- a/gcc/fortran/ChangeLog
+++ b/gcc/fortran/ChangeLog
@@ -1,3 +1,9 @@
+2007-09-18  Francois-Xavier Coudert  <fxcoudert@gcc.gnu.org>
+
+	PR fortran/31119
+	* trans-array.c (gfc_conv_ss_startstride): Only perform bounds
+	checking for optional args when they are present.
+
 2007-09-18  Tobias Burnus  <burnus@net-b.de>
 
 	PR fortran/33231
diff --git a/gcc/fortran/trans-array.c b/gcc/fortran/trans-array.c
index 1e02b81167fafd2b068a68d7facb1fc31898a303..64a62dbd018d62be050f2f0bd9721414c375ff03 100644
--- a/gcc/fortran/trans-array.c
+++ b/gcc/fortran/trans-array.c
@@ -2993,8 +2993,22 @@ gfc_conv_ss_startstride (gfc_loopinfo * loop)
 	         others against this.  */
 	      if (size[n])
 		{
-		  tree tmp3
-		    = fold_build2 (NE_EXPR, boolean_type_node, tmp, size[n]);
+		  tree tmp3;
+
+		  tmp3 = fold_build2 (NE_EXPR, boolean_type_node, tmp, size[n]);
+
+		  /* For optional arguments, only check bounds if the
+		     argument is present.  */
+		  if (ss->expr->symtree->n.sym->attr.optional
+		      || ss->expr->symtree->n.sym->attr.not_always_present)
+		    {
+		      tree cond;
+
+		      cond = gfc_conv_expr_present (ss->expr->symtree->n.sym);
+		      tmp3 = fold_build2 (TRUTH_AND_EXPR, boolean_type_node,
+					  cond, tmp3);
+		    }
+
 		  asprintf (&msg, "%s, size mismatch for dimension %d "
 			    "of array '%s' (%%ld/%%ld)", gfc_msg_bounds,
 			    info->dim[n]+1, ss->expr->symtree->name);
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 5043613375e409b5e36b368634027e29ad3a529c..b0e1b9fa6cd1ce8f37825dac85cb400feca76af9 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,9 @@
+2007-09-18  Francois-Xavier Coudert  <fxcoudert@gcc.gnu.org>
+
+	PR fortran/31119
+	* gfortran.dg/bounds_check_9.f90: New test.
+	* gfortran.dg/bounds_check_fail_2.f90: New test.
+
 2007-09-18  Paolo Carlini  <pcarlini@suse.de>
 
 	PR c++/33462 (again)
diff --git a/gcc/testsuite/gfortran.dg/bounds_check_9.f90 b/gcc/testsuite/gfortran.dg/bounds_check_9.f90
new file mode 100644
index 0000000000000000000000000000000000000000..c0abd2896ece95821dc844fce39eacd977be29c7
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/bounds_check_9.f90
@@ -0,0 +1,36 @@
+! { dg-do run }
+! { dg-options "-fbounds-check" }
+! PR fortran/31119
+!
+module sub_mod
+contains
+elemental subroutine set_optional(i,idef,iopt)
+  integer, intent(out) :: i
+  integer, intent(in) :: idef
+  integer, intent(in), optional :: iopt
+  if (present(iopt)) then
+    i = iopt
+  else
+    i = idef
+  end if
+  end subroutine set_optional
+
+  subroutine sub(ivec)
+    integer, intent(in), optional :: ivec(:)
+    integer :: ivec_(2)
+    call set_optional(ivec_,(/1,2/))
+    if (any (ivec_ /= (/1, 2/))) call abort
+    call set_optional(ivec_,(/1,2/),ivec)
+    if (present (ivec)) then
+      if (any (ivec_ /= ivec)) call abort
+    else
+      if (any (ivec_ /= (/1, 2/))) call abort
+    end if
+  end subroutine sub
+end module sub_mod
+
+program main
+  use sub_mod, only: sub
+  call sub()
+  call sub((/4,5/))
+end program main
diff --git a/gcc/testsuite/gfortran.dg/bounds_check_fail_2.f90 b/gcc/testsuite/gfortran.dg/bounds_check_fail_2.f90
new file mode 100644
index 0000000000000000000000000000000000000000..bb2c247bf311c683706094bb51580c735ef57a1f
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/bounds_check_fail_2.f90
@@ -0,0 +1,39 @@
+! { dg-do run }
+! { dg-options "-fbounds-check" }
+! { dg-shouldfail "foo" }
+!
+! PR 31119
+module sub_mod
+contains
+  elemental subroutine set_optional(i,idef,iopt)
+    integer, intent(out)          :: i
+    integer, intent(in)           :: idef
+    integer, intent(in), optional :: iopt
+    if (present(iopt)) then
+      i = iopt
+    else
+      i = idef
+    end if
+  end subroutine set_optional
+
+  subroutine sub(ivec)
+    integer          , intent(in), optional :: ivec(:)
+    integer                                 :: ivec_(2)
+    call set_optional(ivec_,(/1,2/))
+    if (any (ivec_ /= (/1,2/))) call abort
+    call set_optional(ivec_,(/1,2/),ivec)
+    if (present (ivec)) then
+      if (any (ivec_ /= ivec)) call abort
+    else
+      if (any (ivec_ /= (/1,2/))) call abort
+    end if
+  end subroutine sub
+end module sub_mod
+
+program main
+  use sub_mod, only: sub
+  call sub()
+  call sub((/4,5/))
+  call sub((/4/))
+end program main
+! { dg-output "Fortran runtime error: Array bound mismatch" }