Re: zpty non-functional?

[Peter Stephenson <p.w.stephenson@ntlworld.com>]

On Sat, 24 Aug 2013 17:01:57 -0700
Bart Schaefer <schaefer@brasslantern.com> wrote:
> I'm a bit
> surprised that calling attachtty() works, because it relies on SHTTY
> having been set to the right thing, and I don't see that anything in
> zpty.c is making sure that slave and SHTTY refer to the same fd; but
> perhaps it always is for some indirect reason ...
> 
> Is it safe/reasonable to add
> 
> 	SHTTY = slave;
> 
> right before the attachtty() call in your patch?

That seems to work, anyway.

I added a test, but if instead of using the pipe I add a string as
arguments to zpty -w it usually fails:  I get some of the string
followed by the whole of the string in the output.  This suggests the
write is doing something weird.

I added the trick to make it use _exit() (as we haven't forked) at the
end of the slave code, but that didn't help --- which it probably
shouldn't anyway for various reasons, but I left it in since it looked
logically correct anyway.

So there's something else to investigate.

diff --git a/Src/Modules/zpty.c b/Src/Modules/zpty.c
index 25ec7df..3821194 100644
--- a/Src/Modules/zpty.c
+++ b/Src/Modules/zpty.c
@@ -344,6 +344,8 @@ newptycmd(char *nam, char *pname, char **args, int echo, int nblock)
 
 	if (get_pty(0, &slave))
 	    exit(1);
+	SHTTY = slave;
+	attachtty(mypid);
 #ifdef TIOCGWINSZ
 	/* Set the window size before associating with the terminal *
 	 * so that we don't get hit with a SIGWINCH.  I'm paranoid. */
@@ -398,6 +400,7 @@ newptycmd(char *nam, char *pname, char **args, int echo, int nblock)
 	opts[INTERACTIVE] = 0;
 	execode(prog, 1, 0, "zpty");
 	stopmsg = 2;
+	mypid = 0; /* trick to ensure we _exit() */
 	zexit(lastval, 0);
     }
     master = movefd(master);
diff --git a/Test/.distfiles b/Test/.distfiles
index 689b695..ab92153 100644
--- a/Test/.distfiles
+++ b/Test/.distfiles
@@ -40,6 +40,7 @@ V04features.ztst
 V05styles.ztst
 V06parameter.ztst
 V07pcre.ztst
+V08zpty.ztst
 Y01completion.ztst
 Y02compmatch.ztst
 Y03arguments.ztst
diff --git a/Test/V08zpty.ztst b/Test/V08zpty.ztst
new file mode 100644
index 0000000..d9d24c5
--- /dev/null
+++ b/Test/V08zpty.ztst
@@ -0,0 +1,20 @@
+# zpty is required by tests of interactive modes of the shell itself.
+# This tests some extra things.
+
+%prep
+
+  if ! zmodload zsh/zpty 2>/dev/null
+  then
+    ZTST_unimplemented="the zsh/zpty module is not available"
+    return 0
+  fi
+
+%test
+
+  zpty cat cat
+  print a line of text | zpty -w cat
+  var=
+  zpty -r cat var && print -r -- ${var%%$'\r\n'}
+  zpty -d cat
+0:zpty with a process that does not set up the terminal
+>a line of text

-- 
Peter Stephenson <p.w.stephenson@ntlworld.com>
Web page now at http://homepage.ntlworld.com/p.w.stephenson/