stty: fix setting of 'extproc' on BSD

This setting is unusual on BSD as it's read normally in the local
flags returned by tcgetattr(), but can only be set with an ioctl.
Setting with tcsetattr() is ignored.

* src/stty.c (NO_SETATTR): A new flag to indicate the setting
is read and displayed like a normal termios flag, but is set
in some other manner.
(main): Skip tcsetattr() for this setting when this flag is set.
Also fixup the exiting 'extproc' processing to handle the
'-extproc' case correctly.
(sane_mode): Skip setting '-extproc' for 'sane' to avoid the error.
This isn't ideal but matches the operation of the BSD native stty.

1 files changed, 20 insertions, 7 deletions

diff --git a/src/stty.c b/src/stty.c
index cc5a9e5b1..c0057f2d7 100644
--- a/src/stty.c
+++ b/src/stty.c
@@ -191,6 +191,7 @@ enum mode_type
 #define SANE_UNSET 2		/* Unset in 'sane' mode. */
 #define REV 4			/* Can be turned off by prepending '-'. */
 #define OMIT 8			/* Don't display value. */
+#define NO_SETATTR 16		/* tcsetattr not used to set mode bits.  */
 
 /* Each mode.  */
 struct mode_info
@@ -342,7 +343,9 @@ static struct mode_info const mode_info[] =
   {"echoke", local, SANE_SET | REV, ECHOKE, 0},
   {"crtkill", local, REV | OMIT, ECHOKE, 0},
 #endif
-#ifdef EXTPROC
+#if defined TIOCEXT
+  {"extproc", local, SANE_UNSET | REV | NO_SETATTR, EXTPROC, 0},
+#elif defined EXTPROC
   {"extproc", local, SANE_UNSET | REV, EXTPROC, 0},
 #endif
 
@@ -1192,6 +1195,7 @@ main (int argc, char **argv)
     {
       char const *arg = argv[k];
       bool match_found = false;
+      bool not_set_attr = false;
       bool reversed = false;
       int i;
 
@@ -1207,8 +1211,13 @@ main (int argc, char **argv)
         {
           if (STREQ (arg, mode_info[i].name))
             {
-              match_found = set_mode (&mode_info[i], reversed, &mode);
-              require_set_attr = true;
+              if ((mode_info[i].flags & NO_SETATTR) == 0)
+                {
+                  match_found = set_mode (&mode_info[i], reversed, &mode);
+                  require_set_attr = true;
+                }
+              else
+                match_found = not_set_attr = true;
               break;
             }
         }
@@ -1236,7 +1245,7 @@ main (int argc, char **argv)
                 }
             }
         }
-      if (!match_found)
+      if (!match_found || not_set_attr)
         {
           if (STREQ (arg, "ispeed"))
             {
@@ -1263,10 +1272,11 @@ main (int argc, char **argv)
               require_set_attr = true;
             }
 #ifdef TIOCEXT
-          else if (STREQ (arg, "extproc") || STREQ (arg, "-extproc"))
+          /* This is the BSD interface to "extproc".
+            Even though it's an lflag, an ioctl is used to set it.  */
+          else if (STREQ (arg, "extproc"))
             {
-              /* This is the BSD interface to "extproc".  */
-              int val = *arg != '-';
+              int val = ! reversed;
 
               if (ioctl (STDIN_FILENO, TIOCEXT, &val) != 0)
                 {
@@ -2192,6 +2202,9 @@ sane_mode (struct termios *mode)
 
   for (i = 0; mode_info[i].name != NULL; ++i)
     {
+      if (mode_info[i].flags & NO_SETATTR)
+        continue;
+
       if (mode_info[i].flags & SANE_SET)
         {
           bitsp = mode_type_flag (mode_info[i].type, mode);