cygtclsh80.exe does not properly in emacs 19.34.6 *shell* buffer

[Selner, Jerrell]

Perhaps this problem has been fixed in a newer version but I thought that it
would be helpful to report it.

I find the *shell* buffer of emacs the best place to run a shell.  All of
the output of commands accumulate in this buffer.  I can delete material
that I do not want and keep material that I do.  I can do searches and also
selectively transfer material to other buffers.  I can save commonly used
commands in emacs registers and insert them when needed.  In many ways, the
emacs *shell* buffer is far superior to the WindowsNT cmd window.

When I tried to run cygtclsh80.exe in the *shell* buffer of emacs 19.34.6
(running on Windows NT 4), none of the strings sent by cygtclsh80.exe to
stdout appeared in the *shell* buffer.  This included the prompt character
and the results of tcl commands that I typed in.  Strings that were sent to
stderr did appear.  tclsh83.exe from scriptics had the same problem.

I was able to track the problem down to the following (thank God for open
source) =>

Tcl_Main calls library function isatty to determine if the Tcl shell is
being run from a terminal.  If the Tcl shell is being run from within the
emacs *shell* buffer, isatty returns 0.  This causes Tcl_Main to initialize
the Tcl standard channels in such a way that strings sent to stdout do not
appear.

My solution: change Tcl_Main such that if the first coommand-line argument
is "-", assume that the Tcl shell is being run from a terminal regardless of
the output of isatty.

void
Tcl_Main(argc, argv, appInitProc)
    int argc;                   /* Number of arguments. */
    char **argv;                /* Array of argument strings. */
    Tcl_AppInitProc *appInitProc;
                                /* Application-specific initialization
                                 * procedure to call after most
                                 * initialization but before starting to
                                 * execute commands. */
{
    Tcl_Obj *prompt1NamePtr = NULL;
    Tcl_Obj *prompt2NamePtr = NULL;
    Tcl_Obj *resultPtr;
    Tcl_Obj *commandPtr = NULL;
    char buffer[1000], *args, *fileName, *bytes;
    int code, gotPartial, tty, length;
    int exitCode = 0;
    Tcl_Channel inChannel, outChannel, errChannel;

    Tcl_FindExecutable(argv[0]);
    interp = Tcl_CreateInterp();
#ifdef TCL_MEM_DEBUG
    Tcl_InitMemory(interp);
    Tcl_CreateCommand(interp, "checkmem", CheckmemCmd, (ClientData) 0,
            (Tcl_CmdDeleteProc *) NULL);
#endif
@   /*
@    * Set the "tcl_interactive" variable.
@      Assume interactive (regardless of output of isatty) if first arg is
"-"    
@    */

@   tty = isatty(0);
@   if ((argc >1) && (argv[1][0] == '-') && (argv[1][1] == '\0'))  {
@       argc--;  /* Delete first argument */
@       argv++;
@       tty = 1;
@   }
@   Tcl_SetVar(interp, "tcl_interactive",
@           ((fileName == NULL) && tty) ? "1" : "0", TCL_GLOBAL_ONLY);
    /*
     * Make command-line arguments available in the Tcl variables "argc"
     * and "argv".  If the first argument doesn't start with a "-" then
     * strip it off and use it as the name of a script file to process.
     */

    fileName = NULL;
    if ((argc > 1) && (argv[1][0] != '-')) {
        fileName = argv[1];
        argc--;
        argv++;
    }
    args = Tcl_Merge(argc-1, argv+1);
    Tcl_SetVar(interp, "argv", args, TCL_GLOBAL_ONLY);
    ckfree(args);
    TclFormatInt(buffer, argc-1);
    Tcl_SetVar(interp, "argc", buffer, TCL_GLOBAL_ONLY);
    Tcl_SetVar(interp, "argv0", (fileName != NULL) ? fileName : argv[0],
            TCL_GLOBAL_ONLY);