re PR libfortran/48618 (Negative unit number in OPEN(...) is sometimes allowed)

2013-03-20  Tilo Schwarz  <tilo@tilo-schwarz.de>

        PR libfortran/48618
        * io/open.c (st_open): Raise error for unit number < 0 only if
        unit number does not exist already.

2013-03-20  Tilo Schwarz  <tilo@tilo-schwarz.de>

        PR libfortran/48618
        * gfortran.dg/open_negative_unit_1.f90: New.

From-SVN: r196805

gcc/testsuite/ChangeLog

+2013-03-20  Tilo Schwarz  <tilo@tilo-schwarz.de>
+
+	PR libfortran/48618
+	* gfortran.dg/open_negative_unit_1.f90: New.
+
 2013-03-19  Ian Bolton  <ian.bolton@arm.com>
 
 	* gcc.target/aarch64/sbc.c: New test.

gcc/testsuite/gfortran.dg/open_negative_unit_1.f90

+! { dg-do run }
+! PR48618 - Negative unit number in OPEN(...) is sometimes allowed
+!
+! Test originally from Janne Blomqvist in PR:
+! http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48618
+
+program nutest
+    implicit none
+    integer id, ios
+
+    open(newunit=id, file="foo.txt", iostat=ios)
+    if (ios /= 0) call abort
+
+    open(id, file="bar.txt", iostat=ios)
+    if (ios /= 0) call abort
+
+    close(id, status="delete")
+
+    open(-10, file="foo.txt", iostat=ios)
+    if (ios == 0) call abort
+end program nutest

libgfortran/ChangeLog

+2013-03-20  Tilo Schwarz  <tilo@tilo-schwarz.de>
+
+	PR libfortran/48618
+	* io/open.c (st_open): Raise error for unit number < 0 only if
+	unit number does not exist already.
+
 2013-03-19  Janne Blomqvist  <jb@gcc.gnu.org>
 
 	* libgfortran.h: Include stdbool.h.

libgfortran/io/open.c

@@ -818,10 +818,6 @@ st_open (st_parameter_open *opp)
 
   flags.convert = conv;
 
-  if (!(opp->common.flags & IOPARM_OPEN_HAS_NEWUNIT) && opp->common.unit < 0)
-    generate_error (&opp->common, LIBERROR_BAD_OPTION,
-		    "Bad unit number in OPEN statement");
-
   if (flags.position != POSITION_UNSPECIFIED
       && flags.access == ACCESS_DIRECT)
     generate_error (&opp->common, LIBERROR_BAD_OPTION,
@@ -848,8 +844,16 @@ st_open (st_parameter_open *opp)
     {
       if ((opp->common.flags & IOPARM_OPEN_HAS_NEWUNIT))
 	opp->common.unit = get_unique_unit_number(opp);
+      else if (opp->common.unit < 0)
+	{
+	  u = find_unit (opp->common.unit);
+	  if (u == NULL) /* Negative unit and no NEWUNIT-created unit found.  */
+	    generate_error (&opp->common, LIBERROR_BAD_OPTION,
+			    "Bad unit number in OPEN statement");
+	}
 
-      u = find_or_create_unit (opp->common.unit);
+      if (u == NULL)
+	u = find_or_create_unit (opp->common.unit);
       if (u->s == NULL)
 	{
 	  u = new_unit (opp, u, &flags);