3 files changed, 7 insertions, 0 deletions
diff --git a/libf2c/libU77/fnum_.c b/libf2c/libU77/fnum_.c
index daf8f3d..27cadec 100644
--- a/libf2c/libU77/fnum_.c
+++ b/libf2c/libU77/fnum_.c
@@ -27,6 +27,10 @@ G77_fnum_0 (integer * lunit)
 {
   if (*lunit >= MXUNIT || *lunit < 0)
     err (1, 101, "fnum");
+
+  if (f__units[*lunit].ufd == NULL)
+    err (1, 114, "fnum");
+
   /* f__units is a table of descriptions for the unit numbers (defined
      in io.h).  Use file descriptor (ufd) and fileno rather than udev
      field since udev is unix specific */
diff --git a/libf2c/libU77/fstat_.c b/libf2c/libU77/fstat_.c
index e978c6a..7fd439c 100644
--- a/libf2c/libU77/fstat_.c
+++ b/libf2c/libU77/fstat_.c
@@ -23,6 +23,7 @@ Boston, MA 02111-1307, USA.  */
 #include "config.h"
 #endif
 #include "f2c.h"
+#include "fio.h"
 #include <sys/types.h>
 #include <sys/stat.h>
 
@@ -34,6 +35,7 @@ G77_fstat_0 (const integer * lunit, integer statb[13])
   int err;
   struct stat buf;
 
+  if (f__init != 1) f_init();
   err = fstat (G77_fnum_0 (lunit), &buf);
   statb[0] = buf.st_dev;
   statb[1] = buf.st_ino;
diff --git a/libf2c/libU77/isatty_.c b/libf2c/libU77/isatty_.c
index fa2f56d..a781f75 100644
--- a/libf2c/libU77/isatty_.c
+++ b/libf2c/libU77/isatty_.c
@@ -30,6 +30,7 @@ extern integer G77_fnum_0 (integer *);
 logical
 G77_isatty_0 (integer * lunit)
 {
+  if (f__init != 1) f_init();
   if (*lunit >= MXUNIT || *lunit < 0)
     err (1, 101, "isatty");
   /* f__units is a table of descriptions for the unit numbers (defined