Merge commit '991debcf36ad518e7e9a53b3ad3a388713ffdc1a' as 'tk8.6'

1 files changed, 2039 insertions, 0 deletions

diff --git a/tk8.6/unix/tkUnixSend.c b/tk8.6/unix/tkUnixSend.c
new file mode 100644
index 0000000..bbbdd77
--- /dev/null
+++ b/tk8.6/unix/tkUnixSend.c
@@ -0,0 +1,2039 @@
+/*
+ * tkUnixSend.c --
+ *
+ *	This file provides functions that implement the "send" command,
+ *	allowing commands to be passed from interpreter to interpreter.
+ *
+ * Copyright (c) 1989-1994 The Regents of the University of California.
+ * Copyright (c) 1994-1996 Sun Microsystems, Inc.
+ * Copyright (c) 1998-1999 by Scriptics Corporation.
+ *
+ * See the file "license.terms" for information on usage and redistribution of
+ * this file, and for a DISCLAIMER OF ALL WARRANTIES.
+ */
+
+#include "tkUnixInt.h"
+
+/*
+ * The following structure is used to keep track of the interpreters
+ * registered by this process.
+ */
+
+typedef struct RegisteredInterp {
+    char *name;			/* Interpreter's name (malloc-ed). */
+    Tcl_Interp *interp;		/* Interpreter associated with name. NULL
+				 * means that the application was unregistered
+				 * or deleted while a send was in progress to
+				 * it. */
+    TkDisplay *dispPtr;		/* Display for the application. Needed because
+				 * we may need to unregister the interpreter
+				 * after its main window has been deleted. */
+    struct RegisteredInterp *nextPtr;
+				/* Next in list of names associated with
+				 * interps in this process. NULL means end of
+				 * list. */
+} RegisteredInterp;
+
+/*
+ * A registry of all interpreters for a display is kept in a property
+ * "InterpRegistry" on the root window of the display. It is organized as a
+ * series of zero or more concatenated strings (in no particular order), each
+ * of the form
+ * 	window space name '\0'
+ * where "window" is the hex id of the comm. window to use to talk to an
+ * interpreter named "name".
+ *
+ * When the registry is being manipulated by an application (e.g. to add or
+ * remove an entry), it is loaded into memory using a structure of the
+ * following type:
+ */
+
+typedef struct NameRegistry {
+    TkDisplay *dispPtr;		/* Display from which the registry was
+				 * read. */
+    int locked;			/* Non-zero means that the display was locked
+				 * when the property was read in. */
+    int modified;		/* Non-zero means that the property has been
+				 * modified, so it needs to be written out
+				 * when the NameRegistry is closed. */
+    unsigned long propLength;	/* Length of the property, in bytes. */
+    char *property;		/* The contents of the property, or NULL if
+				 * none. See format description above; this is
+				 * *not* terminated by the first null
+				 * character. Dynamically allocated. */
+    int allocedByX;		/* Non-zero means must free property with
+				 * XFree; zero means use ckfree. */
+} NameRegistry;
+
+/*
+ * When a result is being awaited from a sent command, one of the following
+ * structures is present on a list of all outstanding sent commands. The
+ * information in the structure is used to process the result when it arrives.
+ * You're probably wondering how there could ever be multiple outstanding sent
+ * commands. This could happen if interpreters invoke each other recursively.
+ * It's unlikely, but possible.
+ */
+
+typedef struct PendingCommand {
+    int serial;			/* Serial number expected in result. */
+    TkDisplay *dispPtr;		/* Display being used for communication. */
+    const char *target;		/* Name of interpreter command is being sent
+				 * to. */
+    Window commWindow;		/* Target's communication window. */
+    Tcl_Interp *interp;		/* Interpreter from which the send was
+				 * invoked. */
+    int code;			/* Tcl return code for command will be stored
+				 * here. */
+    char *result;		/* String result for command (malloc'ed), or
+				 * NULL. */
+    char *errorInfo;		/* Information for "errorInfo" variable, or
+				 * NULL (malloc'ed). */
+    char *errorCode;		/* Information for "errorCode" variable, or
+				 * NULL (malloc'ed). */
+    int gotResponse;		/* 1 means a response has been received, 0
+				 * means the command is still outstanding. */
+    struct PendingCommand *nextPtr;
+				/* Next in list of all outstanding commands.
+				 * NULL means end of list. */
+} PendingCommand;
+
+typedef struct ThreadSpecificData {
+    PendingCommand *pendingCommands;
+				/* List of all commands currently being waited
+				 * for. */
+    RegisteredInterp *interpListPtr;
+				/* List of all interpreters registered in the
+				 * current process. */
+} ThreadSpecificData;
+static Tcl_ThreadDataKey dataKey;
+
+/*
+ * The information below is used for communication between processes during
+ * "send" commands. Each process keeps a private window, never even mapped,
+ * with one property, "Comm". When a command is sent to an interpreter, the
+ * command is appended to the comm property of the communication window
+ * associated with the interp's process. Similarly, when a result is returned
+ * from a sent command, it is also appended to the comm property.
+ *
+ * Each command and each result takes the form of ASCII text. For a command,
+ * the text consists of a zero character followed by several null-terminated
+ * ASCII strings. The first string consists of the single letter "c".
+ * Subsequent strings have the form "option value" where the following options
+ * are supported:
+ *
+ * -r commWindow serial
+ *
+ *	This option means that a response should be sent to the window whose X
+ *	identifier is "commWindow" (in hex), and the response should be
+ *	identified with the serial number given by "serial" (in decimal). If
+ *	this option isn't specified then the send is asynchronous and no
+ *	response is sent.
+ *
+ * -n name
+ *
+ *	"Name" gives the name of the application for which the command is
+ *	intended. This option must be present.
+ *
+ * -s script
+ *
+ *	"Script" is the script to be executed. This option must be present.
+ *
+ * The options may appear in any order. The -n and -s options must be present,
+ * but -r may be omitted for asynchronous RPCs. For compatibility with future
+ * releases that may add new features, there may be additional options
+ * present; as long as they start with a "-" character, they will be ignored.
+ *
+ * A result also consists of a zero character followed by several null-
+ * terminated ASCII strings. The first string consists of the single letter
+ * "r". Subsequent strings have the form "option value" where the following
+ * options are supported:
+ *
+ * -s serial
+ *
+ *	Identifies the command for which this is the result. It is the same as
+ *	the "serial" field from the -s option in the command. This option must
+ *	be present.
+ *
+ * -c code
+ *
+ *	"Code" is the completion code for the script, in decimal. If the code
+ *	is omitted it defaults to TCL_OK.
+ *
+ * -r result
+ *
+ *	"Result" is the result string for the script, which may be either a
+ *	result or an error message. If this field is omitted then it defaults
+ *	to an empty string.
+ *
+ * -i errorInfo
+ *
+ *	"ErrorInfo" gives a string with which to initialize the errorInfo
+ *	variable. This option may be omitted; it is ignored unless the
+ *	completion code is TCL_ERROR.
+ *
+ * -e errorCode
+ *
+ *	"ErrorCode" gives a string with with to initialize the errorCode
+ *	variable. This option may be omitted; it is ignored unless the
+ *	completion code is TCL_ERROR.
+ *
+ * Options may appear in any order, and only the -s option must be present. As
+ * with commands, there may be additional options besides these; unknown
+ * options are ignored.
+ */
+
+/*
+ * Other miscellaneous per-process data:
+ */
+
+static struct {
+    int sendSerial;		/* The serial number that was used in the last
+				 * "send" command. */
+    int sendDebug;		/* This can be set while debugging to do
+				 * things like skip locking the server. */
+} localData = {0, 0};
+
+/*
+ * Maximum size property that can be read at one time by this module:
+ */
+
+#define MAX_PROP_WORDS 100000
+
+/*
+ * Forward declarations for functions defined later in this file:
+ */
+
+static int		AppendErrorProc(ClientData clientData,
+			    XErrorEvent *errorPtr);
+static void		AppendPropCarefully(Display *display,
+			    Window window, Atom property, char *value,
+			    int length, PendingCommand *pendingPtr);
+static void		DeleteProc(ClientData clientData);
+static void		RegAddName(NameRegistry *regPtr,
+			    const char *name, Window commWindow);
+static void		RegClose(NameRegistry *regPtr);
+static void		RegDeleteName(NameRegistry *regPtr, const char *name);
+static Window		RegFindName(NameRegistry *regPtr, const char *name);
+static NameRegistry *	RegOpen(Tcl_Interp *interp,
+			    TkDisplay *dispPtr, int lock);
+static void		SendEventProc(ClientData clientData, XEvent *eventPtr);
+static int		SendInit(Tcl_Interp *interp, TkDisplay *dispPtr);
+static Tk_RestrictProc SendRestrictProc;
+static int		ServerSecure(TkDisplay *dispPtr);
+static void		UpdateCommWindow(TkDisplay *dispPtr);
+static int		ValidateName(TkDisplay *dispPtr, const char *name,
+			    Window commWindow, int oldOK);
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * RegOpen --
+ *
+ *	This function loads the name registry for a display into memory so
+ *	that it can be manipulated.
+ *
+ * Results:
+ *	The return value is a pointer to the loaded registry.
+ *
+ * Side effects:
+ *	If "lock" is set then the server will be locked. It is the caller's
+ *	responsibility to call RegClose when finished with the registry, so
+ *	that we can write back the registry if needed, unlock the server if
+ *	needed, and free memory.
+ *
+ *----------------------------------------------------------------------
+ */
+
+static NameRegistry *
+RegOpen(
+    Tcl_Interp *interp,		/* Interpreter to use for error reporting
+				 * (errors cause a panic so in fact no error
+				 * is ever returned, but the interpreter is
+				 * needed anyway). */
+    TkDisplay *dispPtr,		/* Display whose name registry is to be
+				 * opened. */
+    int lock)			/* Non-zero means lock the window server when
+				 * opening the registry, so no-one else can
+				 * use the registry until we close it. */
+{
+    NameRegistry *regPtr;
+    int result, actualFormat;
+    unsigned long bytesAfter;
+    Atom actualType;
+    char **propertyPtr;
+
+    if (dispPtr->commTkwin == NULL) {
+	SendInit(interp, dispPtr);
+    }
+
+    regPtr = ckalloc(sizeof(NameRegistry));
+    regPtr->dispPtr = dispPtr;
+    regPtr->locked = 0;
+    regPtr->modified = 0;
+    regPtr->allocedByX = 1;
+    propertyPtr = &regPtr->property;
+
+    if (lock && !localData.sendDebug) {
+	XGrabServer(dispPtr->display);
+	regPtr->locked = 1;
+    }
+
+    /*
+     * Read the registry property.
+     */
+
+    result = XGetWindowProperty(dispPtr->display,
+	    RootWindow(dispPtr->display, 0),
+	    dispPtr->registryProperty, 0, MAX_PROP_WORDS,
+	    False, XA_STRING, &actualType, &actualFormat,
+	    &regPtr->propLength, &bytesAfter,
+	    (unsigned char **) propertyPtr);
+
+    if (actualType == None) {
+	regPtr->propLength = 0;
+	regPtr->property = NULL;
+    } else if ((result != Success) || (actualFormat != 8)
+	    || (actualType != XA_STRING)) {
+	/*
+	 * The property is improperly formed; delete it.
+	 */
+
+	if (regPtr->property != NULL) {
+	    XFree(regPtr->property);
+	    regPtr->propLength = 0;
+	    regPtr->property = NULL;
+	}
+	XDeleteProperty(dispPtr->display,
+		RootWindow(dispPtr->display, 0),
+		dispPtr->registryProperty);
+    }
+
+    /*
+     * Xlib placed an extra null byte after the end of the property, just to
+     * make sure that it is always NULL-terminated. Be sure to include this
+     * byte in our count if it's needed to ensure null termination (note: as
+     * of 8/95 I'm no longer sure why this code is needed; seems like it
+     * shouldn't be).
+     */
+
+    if ((regPtr->propLength > 0)
+	    && (regPtr->property[regPtr->propLength-1] != 0)) {
+	regPtr->propLength++;
+    }
+    return regPtr;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * RegFindName --
+ *
+ *	Given an open name registry, this function finds an entry with a given
+ *	name, if there is one, and returns information about that entry.
+ *
+ * Results:
+ *	The return value is the X identifier for the comm window for the
+ *	application named "name", or None if there is no such entry in the
+ *	registry.
+ *
+ * Side effects:
+ *	None.
+ *
+ *----------------------------------------------------------------------
+ */
+
+static Window
+RegFindName(
+    NameRegistry *regPtr,	/* Pointer to a registry opened with a
+				 * previous call to RegOpen. */
+    const char *name)		/* Name of an application. */
+{
+    char *p;
+
+    for (p=regPtr->property ; p-regPtr->property<(int)regPtr->propLength ;) {
+	char *entry = p;
+
+	while ((*p != 0) && (!isspace(UCHAR(*p)))) {
+	    p++;
+	}
+	if ((*p != 0) && (strcmp(name, p+1) == 0)) {
+	    unsigned id;
+
+	    if (sscanf(entry, "%x", &id) == 1) {
+		/*
+		 * Must cast from an unsigned int to a Window in case we are
+		 * on a 64-bit architecture.
+		 */
+
+		return (Window) id;
+	    }
+	}
+	while (*p != 0) {
+	    p++;
+	}
+	p++;
+    }
+    return None;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * RegDeleteName --
+ *
+ *	This function deletes the entry for a given name from an open
+ *	registry.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	If there used to be an entry named "name" in the registry, then it is
+ *	deleted and the registry is marked as modified so it will be written
+ *	back when closed.
+ *
+ *----------------------------------------------------------------------
+ */
+
+static void
+RegDeleteName(
+    NameRegistry *regPtr,	/* Pointer to a registry opened with a
+				 * previous call to RegOpen. */
+    const char *name)		/* Name of an application. */
+{
+    char *p;
+
+    for (p=regPtr->property ; p-regPtr->property<(int)regPtr->propLength ;) {
+	char *entry = p, *entryName;
+
+	while ((*p != 0) && (!isspace(UCHAR(*p)))) {
+	    p++;
+	}
+	if (*p != 0) {
+	    p++;
+	}
+	entryName = p;
+	while (*p != 0) {
+	    p++;
+	}
+	p++;
+	if (strcmp(name, entryName) == 0) {
+	    int count;
+
+	    /*
+	     * Found the matching entry. Copy everything after it down on top
+	     * of it.
+	     */
+
+	    count = regPtr->propLength - (p - regPtr->property);
+	    if (count > 0) {
+		char *src, *dst;
+
+		for (src=p , dst=entry ; count>0 ; src++, dst++, count--) {
+		    *dst = *src;
+		}
+	    }
+	    regPtr->propLength -= p - entry;
+	    regPtr->modified = 1;
+	    return;
+	}
+    }
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * RegAddName --
+ *
+ *	Add a new entry to an open registry.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	The open registry is expanded; it is marked as modified so that it
+ *	will be written back when closed.
+ *
+ *----------------------------------------------------------------------
+ */
+
+static void
+RegAddName(
+    NameRegistry *regPtr,	/* Pointer to a registry opened with a
+				 * previous call to RegOpen. */
+    const char *name,		/* Name of an application. The caller must
+				 * ensure that this name isn't already
+				 * registered. */
+    Window commWindow)		/* X identifier for comm. window of
+				 * application. */
+{
+    char id[30], *newProp;
+    int idLength, newBytes;
+
+    sprintf(id, "%x ", (unsigned) commWindow);
+    idLength = strlen(id);
+    newBytes = idLength + strlen(name) + 1;
+    newProp = ckalloc(regPtr->propLength + newBytes);
+    strcpy(newProp, id);
+    strcpy(newProp+idLength, name);
+    if (regPtr->property != NULL) {
+	memcpy(newProp + newBytes, regPtr->property, regPtr->propLength);
+	if (regPtr->allocedByX) {
+	    XFree(regPtr->property);
+	} else {
+	    ckfree(regPtr->property);
+	}
+    }
+    regPtr->modified = 1;
+    regPtr->propLength += newBytes;
+    regPtr->property = newProp;
+    regPtr->allocedByX = 0;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * RegClose --
+ *
+ *	This function is called to end a series of operations on a name
+ *	registry.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	The registry is written back if it has been modified, and the X server
+ *	is unlocked if it was locked. Memory for the registry is freed, so the
+ *	caller should never use regPtr again.
+ *
+ *----------------------------------------------------------------------
+ */
+
+static void
+RegClose(
+    NameRegistry *regPtr)	/* Pointer to a registry opened with a
+				 * previous call to RegOpen. */
+{
+    if (regPtr->modified) {
+	if (!regPtr->locked && !localData.sendDebug) {
+	    Tcl_Panic("The name registry was modified without being locked!");
+	}
+	XChangeProperty(regPtr->dispPtr->display,
+		RootWindow(regPtr->dispPtr->display, 0),
+		regPtr->dispPtr->registryProperty, XA_STRING, 8,
+		PropModeReplace, (unsigned char *) regPtr->property,
+		(int) regPtr->propLength);
+    }
+
+    if (regPtr->locked) {
+	XUngrabServer(regPtr->dispPtr->display);
+    }
+
+    /*
+     * After ungrabbing the server, it's important to flush the output
+     * immediately so that the server sees the ungrab command. Otherwise we
+     * might do something else that needs to communicate with the server (such
+     * as invoking a subprocess that needs to do I/O to the screen); if the
+     * ungrab command is still sitting in our output buffer, we could
+     * deadlock.
+     */
+
+    XFlush(regPtr->dispPtr->display);
+
+    if (regPtr->property != NULL) {
+	if (regPtr->allocedByX) {
+	    XFree(regPtr->property);
+	} else {
+	    ckfree(regPtr->property);
+	}
+    }
+    ckfree(regPtr);
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * ValidateName --
+ *
+ *	This function checks to see if an entry in the registry is still
+ *	valid.
+ *
+ * Results:
+ *	The return value is 1 if the given commWindow exists and its name is
+ *	"name". Otherwise 0 is returned.
+ *
+ * Side effects:
+ *	None.
+ *
+ *----------------------------------------------------------------------
+ */
+
+static int
+ValidateName(
+    TkDisplay *dispPtr,		/* Display for which to perform the
+				 * validation. */
+    const char *name,		/* The name of an application. */
+    Window commWindow,		/* X identifier for the application's comm.
+				 * window. */
+    int oldOK)			/* Non-zero means that we should consider an
+				 * application to be valid even if it looks
+				 * like an old-style (pre-4.0) one; 0 means
+				 * consider these invalid. */
+{
+    int result, actualFormat, argc, i;
+    unsigned long length, bytesAfter;
+    Atom actualType;
+    char *property, **propertyPtr = &property;
+    Tk_ErrorHandler handler;
+    const char **argv;
+
+    property = NULL;
+
+    /*
+     * Ignore X errors when reading the property (e.g., the window might not
+     * exist). If an error occurs, result will be some value other than
+     * Success.
+     */
+
+    handler = Tk_CreateErrorHandler(dispPtr->display, -1, -1, -1, NULL, NULL);
+    result = XGetWindowProperty(dispPtr->display, commWindow,
+	    dispPtr->appNameProperty, 0, MAX_PROP_WORDS,
+	    False, XA_STRING, &actualType, &actualFormat,
+	    &length, &bytesAfter, (unsigned char **) propertyPtr);
+
+    if ((result == Success) && (actualType == None)) {
+	XWindowAttributes atts;
+
+	/*
+	 * The comm. window exists but the property we're looking for doesn't
+	 * exist. This probably means that the application comes from an older
+	 * version of Tk (< 4.0) that didn't set the property; if this is the
+	 * case, then assume for compatibility's sake that everything's OK.
+	 * However, it's also possible that some random application has
+	 * re-used the window id for something totally unrelated. Check a few
+	 * characteristics of the window, such as its dimensions and mapped
+	 * state, to be sure that it still "smells" like a commWindow.
+	 */
+
+	if (!oldOK
+		|| !XGetWindowAttributes(dispPtr->display, commWindow, &atts)
+		|| (atts.width != 1) || (atts.height != 1)
+		|| (atts.map_state != IsUnmapped)) {
+	    result = 0;
+	} else {
+	    result = 1;
+	}
+    } else if ((result == Success) && (actualFormat == 8)
+	    && (actualType == XA_STRING)) {
+	result = 0;
+	if (Tcl_SplitList(NULL, property, &argc, &argv) == TCL_OK) {
+	    for (i = 0; i < argc; i++) {
+		if (strcmp(argv[i], name) == 0) {
+		    result = 1;
+		    break;
+		}
+	    }
+	    ckfree(argv);
+	}
+    } else {
+	result = 0;
+    }
+    Tk_DeleteErrorHandler(handler);
+    if (property != NULL) {
+	XFree(property);
+    }
+    return result;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * ServerSecure --
+ *
+ *	Check whether a server is secure enough for us to trust Tcl scripts
+ *	arriving via that server.
+ *
+ * Results:
+ *	The return value is 1 if the server is secure, which means that
+ *	host-style authentication is turned on but there are no hosts in the
+ *	enabled list. This means that some other form of authorization
+ *	(presumably more secure, such as xauth) is in use.
+ *
+ * Side effects:
+ *	None.
+ *
+ *----------------------------------------------------------------------
+ */
+
+static int
+ServerSecure(
+    TkDisplay *dispPtr)		/* Display to check. */
+{
+#ifdef TK_NO_SECURITY
+    return 1;
+#else
+    XHostAddress *addrPtr;
+    int numHosts, secure;
+    Bool enabled;
+
+    addrPtr = XListHosts(dispPtr->display, &numHosts, &enabled);
+    if (!enabled) {
+    insecure:
+	secure = 0;
+    } else if (numHosts == 0) {
+	secure = 1;
+    } else {
+	/*
+	 * Recent versions of X11 have the extra feature of allowing more
+	 * sophisticated authorization checks to be performed than the dozy
+	 * old ones that used to plague xhost usage. However, not all deployed
+	 * versions of Xlib know how to deal with this feature, so this code
+	 * is conditional on having the right #def in place. [Bug 1909931]
+	 *
+	 * Note that at this point we know that there's at least one entry in
+	 * the list returned by XListHosts. However there may be multiple
+	 * entries; as long as each is one of either 'SI:localhost:*' or
+	 * 'SI:localgroup:*' then we will claim to be secure enough.
+	 */
+
+#ifdef FamilyServerInterpreted
+	XServerInterpretedAddress *siPtr;
+	int i;
+
+	for (i=0 ; i<numHosts ; i++) {
+	    if (addrPtr[i].family != FamilyServerInterpreted) {
+		/*
+		 * We don't understand what the X server is letting in, so we
+		 * err on the side of safety.
+		 */
+
+		goto insecure;
+	    }
+	    siPtr = (XServerInterpretedAddress *) addrPtr[0].address;
+
+	    /*
+	     * We don't check the username or group here. This is because it's
+	     * officially non-portable and we are just making sure there
+	     * aren't silly misconfigurations. (Apparently 'root' is not a
+	     * very good choice, but we still don't put any effort in to spot
+	     * that.) However we do check to see that the constraints are
+	     * imposed against the connecting user and/or group.
+	     */
+
+	    if (       !(siPtr->typelength == 9 /* ==strlen("localuser") */
+			&& !memcmp(siPtr->type, "localuser", 9))
+		    && !(siPtr->typelength == 10 /* ==strlen("localgroup") */
+			&& !memcmp(siPtr->type, "localgroup", 10))) {
+		/*
+		 * The other defined types of server-interpreted controls
+		 * involve particular hosts. These are still insecure for the
+		 * same reasons that classic xhost access is insecure; there's
+		 * just no way to be sure that the users on those systems are
+		 * the ones who should be allowed to connect to this display.
+		 */
+
+		goto insecure;
+	    }
+	}
+	secure = 1;
+#else
+	/*
+	 * We don't understand what the X server is letting in, so we err on
+	 * the side of safety.
+	 */
+
+	secure = 0;
+#endif /* FamilyServerInterpreted */
+    }
+    if (addrPtr != NULL) {
+	XFree((char *) addrPtr);
+    }
+    return secure;
+#endif /* TK_NO_SECURITY */
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * Tk_SetAppName --
+ *
+ *	This function is called to associate an ASCII name with a Tk
+ *	application. If the application has already been named, the name
+ *	replaces the old one.
+ *
+ * Results:
+ *	The return value is the name actually given to the application. This
+ *	will normally be the same as name, but if name was already in use for
+ *	an application then a name of the form "name #2" will be chosen, with
+ *	a high enough number to make the name unique.
+ *
+ * Side effects:
+ *	Registration info is saved, thereby allowing the "send" command to be
+ *	used later to invoke commands in the application. In addition, the
+ *	"send" command is created in the application's interpreter. The
+ *	registration will be removed automatically if the interpreter is
+ *	deleted or the "send" command is removed.
+ *
+ *----------------------------------------------------------------------
+ */
+
+const char *
+Tk_SetAppName(
+    Tk_Window tkwin,		/* Token for any window in the application to
+				 * be named: it is just used to identify the
+				 * application and the display. */
+    const char *name)		/* The name that will be used to refer to the
+				 * interpreter in later "send" commands. Must
+				 * be globally unique. */
+{
+    RegisteredInterp *riPtr, *riPtr2;
+    Window w;
+    TkWindow *winPtr = (TkWindow *) tkwin;
+    TkDisplay *dispPtr = winPtr->dispPtr;
+    NameRegistry *regPtr;
+    Tcl_Interp *interp;
+    const char *actualName;
+    Tcl_DString dString;
+    int offset, i;
+    ThreadSpecificData *tsdPtr =
+	    Tcl_GetThreadData(&dataKey, sizeof(ThreadSpecificData));
+
+    interp = winPtr->mainPtr->interp;
+    if (dispPtr->commTkwin == NULL) {
+	SendInit(interp, winPtr->dispPtr);
+    }
+
+    /*
+     * See if the application is already registered; if so, remove its current
+     * name from the registry.
+     */
+
+    regPtr = RegOpen(interp, winPtr->dispPtr, 1);
+    for (riPtr = tsdPtr->interpListPtr; ; riPtr = riPtr->nextPtr) {
+	if (riPtr == NULL) {
+	    /*
+	     * This interpreter isn't currently registered; create the data
+	     * structure that will be used to register it locally, plus add
+	     * the "send" command to the interpreter.
+	     */
+
+	    riPtr = ckalloc(sizeof(RegisteredInterp));
+	    riPtr->interp = interp;
+	    riPtr->dispPtr = winPtr->dispPtr;
+	    riPtr->nextPtr = tsdPtr->interpListPtr;
+	    tsdPtr->interpListPtr = riPtr;
+	    riPtr->name = NULL;
+	    Tcl_CreateObjCommand(interp, "send", Tk_SendObjCmd, riPtr, DeleteProc);
+	    if (Tcl_IsSafe(interp)) {
+		Tcl_HideCommand(interp, "send", "send");
+	    }
+	    break;
+	}
+	if (riPtr->interp == interp) {
+	    /*
+	     * The interpreter is currently registered; remove it from the
+	     * name registry.
+	     */
+
+	    if (riPtr->name) {
+		RegDeleteName(regPtr, riPtr->name);
+		ckfree(riPtr->name);
+	    }
+	    break;
+	}
+    }
+
+    /*
+     * Pick a name to use for the application. Use "name" if it's not already
+     * in use. Otherwise add a suffix such as " #2", trying larger and larger
+     * numbers until we eventually find one that is unique.
+     */
+
+    actualName = name;
+    offset = 0;				/* Needed only to avoid "used before
+					 * set" compiler warnings. */
+    for (i = 1; ; i++) {
+	if (i > 1) {
+	    if (i == 2) {
+		Tcl_DStringInit(&dString);
+		Tcl_DStringAppend(&dString, name, -1);
+		Tcl_DStringAppend(&dString, " #", 2);
+		offset = Tcl_DStringLength(&dString);
+		Tcl_DStringSetLength(&dString, offset+TCL_INTEGER_SPACE);
+		actualName = Tcl_DStringValue(&dString);
+	    }
+	    sprintf(Tcl_DStringValue(&dString) + offset, "%d", i);
+	}
+	w = RegFindName(regPtr, actualName);
+	if (w == None) {
+	    break;
+	}
+
+	/*
+	 * The name appears to be in use already, but double-check to be sure
+	 * (perhaps the application died without removing its name from the
+	 * registry?).
+	 */
+
+	if (w == Tk_WindowId(dispPtr->commTkwin)) {
+	    for (riPtr2 = tsdPtr->interpListPtr; riPtr2 != NULL;
+		    riPtr2 = riPtr2->nextPtr) {
+		if ((riPtr2->interp != interp) &&
+			(strcmp(riPtr2->name, actualName) == 0)) {
+		    goto nextSuffix;
+		}
+	    }
+	    RegDeleteName(regPtr, actualName);
+	    break;
+	} else if (!ValidateName(winPtr->dispPtr, actualName, w, 1)) {
+	    RegDeleteName(regPtr, actualName);
+	    break;
+	}
+    nextSuffix:
+	continue;
+    }
+
+    /*
+     * We've now got a name to use. Store it in the name registry and in the
+     * local entry for this application, plus put it in a property on the
+     * commWindow.
+     */
+
+    RegAddName(regPtr, actualName, Tk_WindowId(dispPtr->commTkwin));
+    RegClose(regPtr);
+    riPtr->name = ckalloc(strlen(actualName) + 1);
+    strcpy(riPtr->name, actualName);
+    if (actualName != name) {
+	Tcl_DStringFree(&dString);
+    }
+    UpdateCommWindow(dispPtr);
+
+    return riPtr->name;
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * Tk_SendObjCmd --
+ *
+ *	This function is invoked to process the "send" Tcl command. See the
+ *	user documentation for details on what it does.
+ *
+ * Results:
+ *	A standard Tcl result.
+ *
+ * Side effects:
+ *	See the user documentation.
+ *
+ *--------------------------------------------------------------
+ */
+
+int
+Tk_SendObjCmd(
+    ClientData clientData,	/* Information about sender (only dispPtr
+				 * field is used). */
+    Tcl_Interp *interp,		/* Current interpreter. */
+    int objc,			/* Number of arguments. */
+    Tcl_Obj *const objv[])	/* Argument strings. */
+{
+    enum {
+	SEND_ASYNC, SEND_DISPLAYOF, SEND_LAST
+    };
+    static const char *const sendOptions[] = {
+	"-async",   "-displayof",   "--",  NULL
+    };
+    TkWindow *winPtr;
+    Window commWindow;
+    PendingCommand pending;
+    register RegisteredInterp *riPtr;
+    const char *destName;
+    int result, index, async, i, firstArg;
+    Tk_RestrictProc *prevProc;
+    ClientData prevArg;
+    TkDisplay *dispPtr;
+    Tcl_Time timeout;
+    NameRegistry *regPtr;
+    Tcl_DString request;
+    ThreadSpecificData *tsdPtr =
+	    Tcl_GetThreadData(&dataKey, sizeof(ThreadSpecificData));
+    Tcl_Interp *localInterp;	/* Used when the interpreter to send the
+				 * command to is within the same process. */
+
+    /*
+     * Process options, if any.
+     */
+
+    async = 0;
+    winPtr = (TkWindow *) Tk_MainWindow(interp);
+    if (winPtr == NULL) {
+	return TCL_ERROR;
+    }
+    for (i = 1; i < objc; i++) {
+	if (Tcl_GetIndexFromObjStruct(interp, objv[i], sendOptions,
+		sizeof(char *), "option", 0, &index) != TCL_OK) {
+	    break;
+	}
+	if (index == SEND_ASYNC) {
+	    ++async;
+	} else if (index == SEND_DISPLAYOF) {
+	    winPtr = (TkWindow *) Tk_NameToWindow(interp, Tcl_GetString(objv[++i]),
+		    (Tk_Window) winPtr);
+	    if (winPtr == NULL) {
+		return TCL_ERROR;
+	    }
+	} else if (index == SEND_LAST) {
+	    i++;
+	    break;
+	}
+    }
+
+    if (objc < (i+2)) {
+	Tcl_WrongNumArgs(interp, 1, objv,
+		"?-option value ...? interpName arg ?arg ...?");
+	return TCL_ERROR;
+    }
+    destName = Tcl_GetString(objv[i]);
+    firstArg = i+1;
+
+    dispPtr = winPtr->dispPtr;
+    if (dispPtr->commTkwin == NULL) {
+	SendInit(interp, winPtr->dispPtr);
+    }
+
+    /*
+     * See if the target interpreter is local. If so, execute the command
+     * directly without going through the X server. The only tricky thing is
+     * passing the result from the target interpreter to the invoking
+     * interpreter. Watch out: they could be the same!
+     */
+
+    for (riPtr = tsdPtr->interpListPtr; riPtr != NULL;
+	    riPtr = riPtr->nextPtr) {
+	if ((riPtr->dispPtr != dispPtr)
+		|| (strcmp(riPtr->name, destName) != 0)) {
+	    continue;
+	}
+	Tcl_Preserve(riPtr);
+	localInterp = riPtr->interp;
+	Tcl_Preserve(localInterp);
+	if (firstArg == (objc-1)) {
+	    result = Tcl_EvalEx(localInterp, Tcl_GetString(objv[firstArg]), -1, TCL_EVAL_GLOBAL);
+	} else {
+	    Tcl_DStringInit(&request);
+	    Tcl_DStringAppend(&request, Tcl_GetString(objv[firstArg]), -1);
+	    for (i = firstArg+1; i < objc; i++) {
+		Tcl_DStringAppend(&request, " ", 1);
+		Tcl_DStringAppend(&request, Tcl_GetString(objv[i]), -1);
+	    }
+	    result = Tcl_EvalEx(localInterp, Tcl_DStringValue(&request), -1, TCL_EVAL_GLOBAL);
+	    Tcl_DStringFree(&request);
+	}
+	if (interp != localInterp) {
+	    if (result == TCL_ERROR) {
+		Tcl_Obj *errorObjPtr;
+
+		/*
+		 * An error occurred, so transfer error information from the
+		 * destination interpreter back to our interpreter. Must clear
+		 * interp's result before calling Tcl_AddErrorInfo, since
+		 * Tcl_AddErrorInfo will store the interp's result in
+		 * errorInfo before appending riPtr's $errorInfo; we've
+		 * already got everything we need in riPtr's $errorInfo.
+		 */
+
+		Tcl_ResetResult(interp);
+		Tcl_AddErrorInfo(interp, Tcl_GetVar2(localInterp,
+			"errorInfo", NULL, TCL_GLOBAL_ONLY));
+		errorObjPtr = Tcl_GetVar2Ex(localInterp, "errorCode", NULL,
+			TCL_GLOBAL_ONLY);
+		Tcl_SetObjErrorCode(interp, errorObjPtr);
+	    }
+	    Tcl_SetObjResult(interp, Tcl_GetObjResult(localInterp));
+	    Tcl_ResetResult(localInterp);
+	}
+	Tcl_Release(riPtr);
+	Tcl_Release(localInterp);
+	return result;
+    }
+
+    /*
+     * Bind the interpreter name to a communication window.
+     */
+
+    regPtr = RegOpen(interp, winPtr->dispPtr, 0);
+    commWindow = RegFindName(regPtr, destName);
+    RegClose(regPtr);
+    if (commWindow == None) {
+	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		"no application named \"%s\"", destName));
+	Tcl_SetErrorCode(interp, "TK", "LOOKUP", "APPLICATION", destName,
+		NULL);
+	return TCL_ERROR;
+    }
+
+    /*
+     * Send the command to the target interpreter by appending it to the comm
+     * window in the communication window.
+     */
+
+    localData.sendSerial++;
+    Tcl_DStringInit(&request);
+    Tcl_DStringAppend(&request, "\0c\0-n ", 6);
+    Tcl_DStringAppend(&request, destName, -1);
+    if (!async) {
+	char buffer[TCL_INTEGER_SPACE * 2];
+
+	sprintf(buffer, "%x %d",
+		(unsigned) Tk_WindowId(dispPtr->commTkwin),
+		localData.sendSerial);
+	Tcl_DStringAppend(&request, "\0-r ", 4);
+	Tcl_DStringAppend(&request, buffer, -1);
+    }
+    Tcl_DStringAppend(&request, "\0-s ", 4);
+    Tcl_DStringAppend(&request, Tcl_GetString(objv[firstArg]), -1);
+    for (i = firstArg+1; i < objc; i++) {
+	Tcl_DStringAppend(&request, " ", 1);
+	Tcl_DStringAppend(&request, Tcl_GetString(objv[i]), -1);
+    }
+    (void) AppendPropCarefully(dispPtr->display, commWindow,
+	    dispPtr->commProperty, Tcl_DStringValue(&request),
+	    Tcl_DStringLength(&request) + 1, (async ? NULL : &pending));
+    Tcl_DStringFree(&request);
+    if (async) {
+	/*
+	 * This is an asynchronous send: return immediately without waiting
+	 * for a response.
+	 */
+
+	return TCL_OK;
+    }
+
+    /*
+     * Register the fact that we're waiting for a command to complete (this is
+     * needed by SendEventProc and by AppendErrorProc to pass back the
+     * command's results). Set up a timeout handler so that we can check
+     * during long sends to make sure that the destination application is
+     * still alive.
+     */
+
+    pending.serial = localData.sendSerial;
+    pending.dispPtr = dispPtr;
+    pending.target = destName;
+    pending.commWindow = commWindow;
+    pending.interp = interp;
+    pending.result = NULL;
+    pending.errorInfo = NULL;
+    pending.errorCode = NULL;
+    pending.gotResponse = 0;
+    pending.nextPtr = tsdPtr->pendingCommands;
+    tsdPtr->pendingCommands = &pending;
+
+    /*
+     * Enter a loop processing X events until the result comes in or the
+     * target is declared to be dead. While waiting for a result, look only at
+     * send-related events so that the send is synchronous with respect to
+     * other events in the application.
+     */
+
+    prevProc = Tk_RestrictEvents(SendRestrictProc, NULL, &prevArg);
+    Tcl_GetTime(&timeout);
+    timeout.sec += 2;
+    while (!pending.gotResponse) {
+	if (!TkUnixDoOneXEvent(&timeout)) {
+	    /*
+	     * An unusually long amount of time has elapsed during the
+	     * processing of a sent command. Check to make sure that the
+	     * target application still exists. If it does, reset the timeout.
+	     */
+
+	    if (!ValidateName(pending.dispPtr, pending.target,
+		    pending.commWindow, 0)) {
+		const char *msg;
+
+		if (ValidateName(pending.dispPtr, pending.target,
+			pending.commWindow, 1)) {
+		    msg = "target application died or uses a Tk version before 4.0";
+		} else {
+		    msg = "target application died";
+		}
+		pending.code = TCL_ERROR;
+		pending.result = ckalloc(strlen(msg) + 1);
+		strcpy(pending.result, msg);
+		pending.gotResponse = 1;
+	    } else {
+		Tcl_GetTime(&timeout);
+		timeout.sec += 2;
+	    }
+	}
+    }
+    Tk_RestrictEvents(prevProc, prevArg, &prevArg);
+
+    /*
+     * Unregister the information about the pending command and return the
+     * result.
+     */
+
+    if (tsdPtr->pendingCommands != &pending) {
+	Tcl_Panic("Tk_SendCmd: corrupted send stack");
+    }
+    tsdPtr->pendingCommands = pending.nextPtr;
+    if (pending.errorInfo != NULL) {
+	/*
+	 * Special trick: must clear the interp's result before calling
+	 * Tcl_AddErrorInfo, since Tcl_AddErrorInfo will store the interp's
+	 * result in errorInfo before appending pending.errorInfo; we've
+	 * already got everything we need in pending.errorInfo.
+	 */
+
+	Tcl_ResetResult(interp);
+	Tcl_AddErrorInfo(interp, pending.errorInfo);
+	ckfree(pending.errorInfo);
+    }
+    if (pending.errorCode != NULL) {
+	Tcl_SetObjErrorCode(interp, Tcl_NewStringObj(pending.errorCode, -1));
+	ckfree(pending.errorCode);
+    }
+    Tcl_SetObjResult(interp, Tcl_NewStringObj(pending.result, -1));
+    ckfree(pending.result);
+    return pending.code;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TkGetInterpNames --
+ *
+ *	This function is invoked to fetch a list of all the interpreter names
+ *	currently registered for the display of a particular window.
+ *
+ * Results:
+ *	A standard Tcl return value. The interp's result will be set to hold a
+ *	list of all the interpreter names defined for tkwin's display. If an
+ *	error occurs, then TCL_ERROR is returned and the interp's result will
+ *	hold an error message.
+ *
+ * Side effects:
+ *	None.
+ *
+ *----------------------------------------------------------------------
+ */
+
+int
+TkGetInterpNames(
+    Tcl_Interp *interp,		/* Interpreter for returning a result. */
+    Tk_Window tkwin)		/* Window whose display is to be used for the
+				 * lookup. */
+{
+    TkWindow *winPtr = (TkWindow *) tkwin;
+    NameRegistry *regPtr;
+    Tcl_Obj *resultObj = Tcl_NewObj();
+    char *p;
+
+    /*
+     * Read the registry property, then scan through all of its entries.
+     * Validate each entry to be sure that its application still exists.
+     */
+
+    regPtr = RegOpen(interp, winPtr->dispPtr, 1);
+    for (p=regPtr->property ; p-regPtr->property<(int)regPtr->propLength ;) {
+	char *entry = p, *entryName;
+	Window commWindow;
+	unsigned id;
+
+	if (sscanf(p, "%x", (unsigned *) &id) != 1) {
+	    commWindow = None;
+	} else {
+	    commWindow = id;
+	}
+	while ((*p != 0) && (!isspace(UCHAR(*p)))) {
+	    p++;
+	}
+	if (*p != 0) {
+	    p++;
+	}
+	entryName = p;
+	while (*p != 0) {
+	    p++;
+	}
+	p++;
+	if (ValidateName(winPtr->dispPtr, entryName, commWindow, 1)) {
+	    /*
+	     * The application still exists; add its name to the result.
+	     */
+
+	    Tcl_ListObjAppendElement(NULL, resultObj,
+		    Tcl_NewStringObj(entryName, -1));
+	} else {
+	    int count;
+
+	    /*
+	     * This name is bogus (perhaps the application died without
+	     * cleaning up its entry in the registry?). Delete the name.
+	     */
+
+	    count = regPtr->propLength - (p - regPtr->property);
+	    if (count > 0) {
+		char *src, *dst;
+
+		for (src = p, dst = entry; count > 0; src++, dst++, count--) {
+		    *dst = *src;
+		}
+	    }
+	    regPtr->propLength -= p - entry;
+	    regPtr->modified = 1;
+	    p = entry;
+	}
+    }
+    RegClose(regPtr);
+    Tcl_SetObjResult(interp, resultObj);
+    return TCL_OK;
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * TkSendCleanup --
+ *
+ *	This function is called to free resources used by the communication
+ *	channels for sending commands and receiving results.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	Frees various data structures and windows.
+ *
+ *--------------------------------------------------------------
+ */
+
+void
+TkSendCleanup(
+    TkDisplay *dispPtr)
+{
+    if (dispPtr->commTkwin != NULL) {
+	Tk_DeleteEventHandler(dispPtr->commTkwin, PropertyChangeMask,
+		SendEventProc, dispPtr);
+	Tk_DestroyWindow(dispPtr->commTkwin);
+	Tcl_Release(dispPtr->commTkwin);
+	dispPtr->commTkwin = NULL;
+    }
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * SendInit --
+ *
+ *	This function is called to initialize the communication channels for
+ *	sending commands and receiving results.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	Sets up various data structures and windows.
+ *
+ *--------------------------------------------------------------
+ */
+
+static int
+SendInit(
+    Tcl_Interp *interp,		/* Interpreter to use for error reporting (no
+				 * errors are ever returned, but the
+				 * interpreter is needed anyway). */
+    TkDisplay *dispPtr)		/* Display to initialize. */
+{
+    XSetWindowAttributes atts;
+
+    /*
+     * Create the window used for communication, and set up an event handler
+     * for it.
+     */
+
+    dispPtr->commTkwin = (Tk_Window) TkAllocWindow(dispPtr,
+    	DefaultScreen(dispPtr->display), NULL);
+    Tcl_Preserve(dispPtr->commTkwin);
+    ((TkWindow *) dispPtr->commTkwin)->flags |=
+	    TK_TOP_HIERARCHY|TK_TOP_LEVEL|TK_HAS_WRAPPER|TK_WIN_MANAGED;
+    TkWmNewWindow((TkWindow *) dispPtr->commTkwin);
+    atts.override_redirect = True;
+    Tk_ChangeWindowAttributes(dispPtr->commTkwin,
+	    CWOverrideRedirect, &atts);
+    Tk_CreateEventHandler(dispPtr->commTkwin, PropertyChangeMask,
+	    SendEventProc, dispPtr);
+    Tk_MakeWindowExist(dispPtr->commTkwin);
+
+    /*
+     * Get atoms used as property names.
+     */
+
+    dispPtr->commProperty = Tk_InternAtom(dispPtr->commTkwin, "Comm");
+    dispPtr->registryProperty = Tk_InternAtom(dispPtr->commTkwin,
+	    "InterpRegistry");
+    dispPtr->appNameProperty = Tk_InternAtom(dispPtr->commTkwin,
+	    "TK_APPLICATION");
+
+    return TCL_OK;
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * SendEventProc --
+ *
+ *	This function is invoked automatically by the toolkit event manager
+ *	when a property changes on the communication window. This function
+ *	reads the property and handles command requests and responses.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	If there are command requests in the property, they are executed. If
+ *	there are responses in the property, their information is saved for
+ *	the (ostensibly waiting) "send" commands. The property is deleted.
+ *
+ *--------------------------------------------------------------
+ */
+
+static void
+SendEventProc(
+    ClientData clientData,	/* Display information. */
+    XEvent *eventPtr)		/* Information about event. */
+{
+    TkDisplay *dispPtr = clientData;
+    char *propInfo, **propInfoPtr = &propInfo;
+    const char *p;
+    int result, actualFormat;
+    unsigned long numItems, bytesAfter;
+    Atom actualType;
+    Tcl_Interp *remoteInterp;	/* Interp in which to execute the command. */
+    ThreadSpecificData *tsdPtr =
+	    Tcl_GetThreadData(&dataKey, sizeof(ThreadSpecificData));
+
+    if ((eventPtr->xproperty.atom != dispPtr->commProperty)
+	    || (eventPtr->xproperty.state != PropertyNewValue)) {
+	return;
+    }
+
+    /*
+     * Read the comm property and delete it.
+     */
+
+    propInfo = NULL;
+    result = XGetWindowProperty(dispPtr->display,
+	    Tk_WindowId(dispPtr->commTkwin), dispPtr->commProperty, 0,
+	    MAX_PROP_WORDS, True, XA_STRING, &actualType, &actualFormat,
+	    &numItems, &bytesAfter, (unsigned char **) propInfoPtr);
+
+    /*
+     * If the property doesn't exist or is improperly formed then ignore it.
+     */
+
+    if ((result != Success) || (actualType != XA_STRING)
+	    || (actualFormat != 8)) {
+	if (propInfo != NULL) {
+	    XFree(propInfo);
+	}
+	return;
+    }
+
+    /*
+     * Several commands and results could arrive in the property at one time;
+     * each iteration through the outer loop handles a single command or
+     * result.
+     */
+
+    for (p = propInfo; (p-propInfo) < (int) numItems; ) {
+	/*
+	 * Ignore leading NULLs; each command or result starts with a NULL so
+	 * that no matter how badly formed a preceding command is, we'll be
+	 * able to tell that a new command/result is starting.
+	 */
+
+	if (*p == 0) {
+	    p++;
+	    continue;
+	}
+
+	if ((*p == 'c') && (p[1] == 0)) {
+	    Window commWindow;
+	    const char *interpName, *script, *serial;
+	    char *end;
+	    Tcl_DString reply;
+	    RegisteredInterp *riPtr;
+
+	    /*
+	     *----------------------------------------------------------
+	     * This is an incoming command from some other application.
+	     * Iterate over all of its options. Stop when we reach the end of
+	     * the property or something that doesn't look like an option.
+	     *----------------------------------------------------------
+	     */
+
+	    p += 2;
+	    interpName = NULL;
+	    commWindow = None;
+	    serial = "";
+	    script = NULL;
+	    while (((p-propInfo) < (int) numItems) && (*p == '-')) {
+		switch (p[1]) {
+		case 'r':
+		    commWindow = (Window) strtoul(p+2, &end, 16);
+		    if ((end == p+2) || (*end != ' ')) {
+			commWindow = None;
+		    } else {
+			p = serial = end+1;
+		    }
+		    break;
+		case 'n':
+		    if (p[2] == ' ') {
+			interpName = p+3;
+		    }
+		    break;
+		case 's':
+		    if (p[2] == ' ') {
+			script = p+3;
+		    }
+		    break;
+		}
+		while (*p != 0) {
+		    p++;
+		}
+		p++;
+	    }
+
+	    if ((script == NULL) || (interpName == NULL)) {
+		continue;
+	    }
+
+	    /*
+	     * Initialize the result property, so that we're ready at any time
+	     * if we need to return an error.
+	     */
+
+	    if (commWindow != None) {
+		Tcl_DStringInit(&reply);
+		Tcl_DStringAppend(&reply, "\0r\0-s ", 6);
+		Tcl_DStringAppend(&reply, serial, -1);
+		Tcl_DStringAppend(&reply, "\0-r ", 4);
+	    }
+
+	    if (!ServerSecure(dispPtr)) {
+		if (commWindow != None) {
+		    Tcl_DStringAppend(&reply,
+			    "X server insecure (must use xauth-style "
+			    "authorization); command ignored", -1);
+		}
+		result = TCL_ERROR;
+		goto returnResult;
+	    }
+
+	    /*
+	     * Locate the application, then execute the script.
+	     */
+
+	    for (riPtr = tsdPtr->interpListPtr; ; riPtr = riPtr->nextPtr) {
+		if (riPtr == NULL) {
+		    if (commWindow != None) {
+			Tcl_DStringAppend(&reply,
+				"receiver never heard of interpreter \"", -1);
+			Tcl_DStringAppend(&reply, interpName, -1);
+			Tcl_DStringAppend(&reply, "\"", 1);
+		    }
+		    result = TCL_ERROR;
+		    goto returnResult;
+		}
+		if (strcmp(riPtr->name, interpName) == 0) {
+		    break;
+		}
+	    }
+	    Tcl_Preserve(riPtr);
+
+	    /*
+	     * We must protect the interpreter because the script may enter
+	     * another event loop, which might call Tcl_DeleteInterp.
+	     */
+
+	    remoteInterp = riPtr->interp;
+	    Tcl_Preserve(remoteInterp);
+
+	    result = Tcl_EvalEx(remoteInterp, script, -1, TCL_EVAL_GLOBAL);
+
+	    /*
+	     * The call to Tcl_Release may have released the interpreter which
+	     * will cause the "send" command for that interpreter to be
+	     * deleted. The command deletion callback will set the
+	     * riPtr->interp field to NULL, hence the check below for NULL.
+	     */
+
+	    if (commWindow != None) {
+		Tcl_DStringAppend(&reply, Tcl_GetString(Tcl_GetObjResult(remoteInterp)),
+			-1);
+		if (result == TCL_ERROR) {
+		    const char *varValue;
+
+		    varValue = Tcl_GetVar2(remoteInterp, "errorInfo",
+			    NULL, TCL_GLOBAL_ONLY);
+		    if (varValue != NULL) {
+			Tcl_DStringAppend(&reply, "\0-i ", 4);
+			Tcl_DStringAppend(&reply, varValue, -1);
+		    }
+		    varValue = Tcl_GetVar2(remoteInterp, "errorCode",
+			    NULL, TCL_GLOBAL_ONLY);
+		    if (varValue != NULL) {
+			Tcl_DStringAppend(&reply, "\0-e ", 4);
+			Tcl_DStringAppend(&reply, varValue, -1);
+		    }
+		}
+	    }
+	    Tcl_Release(remoteInterp);
+	    Tcl_Release(riPtr);
+
+	    /*
+	     * Return the result to the sender if a commWindow was specified
+	     * (if none was specified then this is an asynchronous call).
+	     * Right now reply has everything but the completion code, but it
+	     * needs the NULL to terminate the current option.
+	     */
+
+	returnResult:
+	    if (commWindow != None) {
+		if (result != TCL_OK) {
+		    char buffer[TCL_INTEGER_SPACE];
+
+		    sprintf(buffer, "%d", result);
+		    Tcl_DStringAppend(&reply, "\0-c ", 4);
+		    Tcl_DStringAppend(&reply, buffer, -1);
+		}
+		(void) AppendPropCarefully(dispPtr->display, commWindow,
+			dispPtr->commProperty, Tcl_DStringValue(&reply),
+			Tcl_DStringLength(&reply) + 1, NULL);
+		XFlush(dispPtr->display);
+		Tcl_DStringFree(&reply);
+	    }
+	} else if ((*p == 'r') && (p[1] == 0)) {
+	    int serial, code, gotSerial;
+	    const char *errorInfo, *errorCode, *resultString;
+	    PendingCommand *pcPtr;
+
+	    /*
+	     *----------------------------------------------------------
+	     * This is a reply to some command that we sent out. Iterate over
+	     * all of its options. Stop when we reach the end of the property
+	     * or something that doesn't look like an option.
+	     *----------------------------------------------------------
+	     */
+
+	    p += 2;
+	    code = TCL_OK;
+	    gotSerial = 0;
+	    errorInfo = NULL;
+	    errorCode = NULL;
+	    resultString = "";
+	    while (((p-propInfo) < (int) numItems) && (*p == '-')) {
+		switch (p[1]) {
+		case 'c':
+		    if (sscanf(p+2, " %d", &code) != 1) {
+			code = TCL_OK;
+		    }
+		    break;
+		case 'e':
+		    if (p[2] == ' ') {
+			errorCode = p+3;
+		    }
+		    break;
+		case 'i':
+		    if (p[2] == ' ') {
+			errorInfo = p+3;
+		    }
+		    break;
+		case 'r':
+		    if (p[2] == ' ') {
+			resultString = p+3;
+		    }
+		    break;
+		case 's':
+		    if (sscanf(p+2, " %d", &serial) == 1) {
+			gotSerial = 1;
+		    }
+		    break;
+		}
+		while (*p != 0) {
+		    p++;
+		}
+		p++;
+	    }
+
+	    if (!gotSerial) {
+		continue;
+	    }
+
+	    /*
+	     * Give the result information to anyone who's waiting for it.
+	     */
+
+	    for (pcPtr = tsdPtr->pendingCommands; pcPtr != NULL;
+		    pcPtr = pcPtr->nextPtr) {
+		if ((serial != pcPtr->serial) || (pcPtr->result != NULL)) {
+		    continue;
+		}
+		pcPtr->code = code;
+		if (resultString != NULL) {
+		    pcPtr->result = ckalloc(strlen(resultString) + 1);
+		    strcpy(pcPtr->result, resultString);
+		}
+		if (code == TCL_ERROR) {
+		    if (errorInfo != NULL) {
+			pcPtr->errorInfo = ckalloc(strlen(errorInfo) + 1);
+			strcpy(pcPtr->errorInfo, errorInfo);
+		    }
+		    if (errorCode != NULL) {
+			pcPtr->errorCode = ckalloc(strlen(errorCode) + 1);
+			strcpy(pcPtr->errorCode, errorCode);
+		    }
+		}
+		pcPtr->gotResponse = 1;
+		break;
+	    }
+	} else {
+	    /*
+	     * Didn't recognize this thing. Just skip through the next null
+	     * character and try again.
+	     */
+
+	    while (*p != 0) {
+		p++;
+	    }
+	    p++;
+	}
+    }
+    XFree(propInfo);
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * AppendPropCarefully --
+ *
+ *	Append a given property to a given window, but set up an X error
+ *	handler so that if the append fails this function can return an error
+ *	code rather than having Xlib panic.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	The given property on the given window is appended to. If this
+ *	operation fails and if pendingPtr is non-NULL, then the pending
+ *	operation is marked as complete with an error.
+ *
+ *--------------------------------------------------------------
+ */
+
+static void
+AppendPropCarefully(
+    Display *display,		/* Display on which to operate. */
+    Window window,		/* Window whose property is to be modified. */
+    Atom property,		/* Name of property. */
+    char *value,		/* Characters to append to property. */
+    int length,			/* Number of bytes to append. */
+    PendingCommand *pendingPtr)	/* Pending command to mark complete if an
+				 * error occurs during the property op. NULL
+				 * means just ignore the error. */
+{
+    Tk_ErrorHandler handler;
+
+    handler = Tk_CreateErrorHandler(display, -1, -1, -1, AppendErrorProc,
+	    pendingPtr);
+    XChangeProperty(display, window, property, XA_STRING, 8,
+	    PropModeAppend, (unsigned char *) value, length);
+    Tk_DeleteErrorHandler(handler);
+}
+
+/*
+ * The function below is invoked if an error occurs during the XChangeProperty
+ * operation above.
+ */
+
+	/* ARGSUSED */
+static int
+AppendErrorProc(
+    ClientData clientData,	/* Command to mark complete, or NULL. */
+    XErrorEvent *errorPtr)	/* Information about error. */
+{
+    PendingCommand *pendingPtr = clientData;
+    register PendingCommand *pcPtr;
+    ThreadSpecificData *tsdPtr =
+	    Tcl_GetThreadData(&dataKey, sizeof(ThreadSpecificData));
+
+    if (pendingPtr == NULL) {
+	return 0;
+    }
+
+    /*
+     * Make sure this command is still pending.
+     */
+
+    for (pcPtr = tsdPtr->pendingCommands; pcPtr != NULL;
+	    pcPtr = pcPtr->nextPtr) {
+	if ((pcPtr == pendingPtr) && (pcPtr->result == NULL)) {
+	    pcPtr->result = ckalloc(strlen(pcPtr->target) + 50);
+	    sprintf(pcPtr->result, "no application named \"%s\"",
+		    pcPtr->target);
+	    pcPtr->code = TCL_ERROR;
+	    pcPtr->gotResponse = 1;
+	    break;
+	}
+    }
+    return 0;
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * DeleteProc --
+ *
+ *	This function is invoked by Tcl when the "send" command is deleted in
+ *	an interpreter. It unregisters the interpreter.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	The interpreter given by riPtr is unregistered.
+ *
+ *--------------------------------------------------------------
+ */
+
+static void
+DeleteProc(
+    ClientData clientData)	/* Info about registration, passed as
+				 * ClientData. */
+{
+    RegisteredInterp *riPtr = clientData;
+    register RegisteredInterp *riPtr2;
+    NameRegistry *regPtr;
+    ThreadSpecificData *tsdPtr =
+	    Tcl_GetThreadData(&dataKey, sizeof(ThreadSpecificData));
+
+    regPtr = RegOpen(riPtr->interp, riPtr->dispPtr, 1);
+    RegDeleteName(regPtr, riPtr->name);
+    RegClose(regPtr);
+
+    if (tsdPtr->interpListPtr == riPtr) {
+	tsdPtr->interpListPtr = riPtr->nextPtr;
+    } else {
+	for (riPtr2 = tsdPtr->interpListPtr; riPtr2 != NULL;
+		riPtr2 = riPtr2->nextPtr) {
+	    if (riPtr2->nextPtr == riPtr) {
+		riPtr2->nextPtr = riPtr->nextPtr;
+		break;
+	    }
+	}
+    }
+    ckfree(riPtr->name);
+    riPtr->interp = NULL;
+    UpdateCommWindow(riPtr->dispPtr);
+    Tcl_EventuallyFree(riPtr, TCL_DYNAMIC);
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * SendRestrictProc --
+ *
+ *	This function filters incoming events when a "send" command is
+ *	outstanding. It defers all events except those containing send
+ *	commands and results.
+ *
+ * Results:
+ *	False is returned except for property-change events on a commWindow.
+ *
+ * Side effects:
+ *	None.
+ *
+ *----------------------------------------------------------------------
+ */
+
+    /* ARGSUSED */
+static Tk_RestrictAction
+SendRestrictProc(
+    ClientData clientData,		/* Not used. */
+    register XEvent *eventPtr)		/* Event that just arrived. */
+{
+    TkDisplay *dispPtr;
+
+    if (eventPtr->type != PropertyNotify) {
+	return TK_DEFER_EVENT;
+    }
+    for (dispPtr = TkGetDisplayList(); dispPtr != NULL;
+	    dispPtr = dispPtr->nextPtr) {
+	if ((eventPtr->xany.display == dispPtr->display)
+		&& (eventPtr->xproperty.window
+		== Tk_WindowId(dispPtr->commTkwin))) {
+	    return TK_PROCESS_EVENT;
+	}
+    }
+    return TK_DEFER_EVENT;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * UpdateCommWindow --
+ *
+ *	This function updates the list of application names stored on our
+ *	commWindow. It is typically called when interpreters are registered
+ *	and unregistered.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	The TK_APPLICATION property on the comm window is updated.
+ *
+ *----------------------------------------------------------------------
+ */
+
+static void
+UpdateCommWindow(
+    TkDisplay *dispPtr)		/* Display whose commWindow is to be
+				 * updated. */
+{
+    Tcl_DString names;
+    RegisteredInterp *riPtr;
+    ThreadSpecificData *tsdPtr =
+	    Tcl_GetThreadData(&dataKey, sizeof(ThreadSpecificData));
+
+    Tcl_DStringInit(&names);
+    for (riPtr = tsdPtr->interpListPtr; riPtr != NULL;
+	    riPtr = riPtr->nextPtr) {
+	Tcl_DStringAppendElement(&names, riPtr->name);
+    }
+    XChangeProperty(dispPtr->display, Tk_WindowId(dispPtr->commTkwin),
+	    dispPtr->appNameProperty, XA_STRING, 8, PropModeReplace,
+	    (unsigned char *) Tcl_DStringValue(&names),
+	    Tcl_DStringLength(&names));
+    Tcl_DStringFree(&names);
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TkpTestsendCmd --
+ *
+ *	This function implements the "testsend" command. It provides a set of
+ *	functions for testing the "send" command and support function in
+ *	tkSend.c.
+ *
+ * Results:
+ *	A standard Tcl result.
+ *
+ * Side effects:
+ *	Depends on option; see below.
+ *
+ *----------------------------------------------------------------------
+ */
+
+	/* ARGSUSED */
+int
+TkpTestsendCmd(
+    ClientData clientData,	/* Main window for application. */
+    Tcl_Interp *interp,		/* Current interpreter. */
+    int objc,			/* Number of arguments. */
+    Tcl_Obj *const objv[])		/* Argument strings. */
+{
+    enum {
+	TESTSEND_BOGUS, TESTSEND_PROP, TESTSEND_SERIAL
+    };
+    static const char *const testsendOptions[] = {
+	"bogus",   "prop",   "serial",  NULL
+    };
+    TkWindow *winPtr = clientData;
+    int index;
+
+    if (objc < 2) {
+	Tcl_WrongNumArgs(interp, 1, objv,
+		"option ?arg ...?");
+	return TCL_ERROR;
+    }
+
+	if (Tcl_GetIndexFromObjStruct(interp, objv[1], testsendOptions,
+		sizeof(char *), "option", 0, &index) != TCL_OK) {
+	    return TCL_ERROR;
+	}
+	if (index == TESTSEND_BOGUS) {
+	XChangeProperty(winPtr->dispPtr->display,
+		RootWindow(winPtr->dispPtr->display, 0),
+		winPtr->dispPtr->registryProperty, XA_INTEGER, 32,
+		PropModeReplace,
+		(unsigned char *) "This is bogus information", 6);
+    } else if (index == TESTSEND_PROP) {
+	int result, actualFormat;
+	unsigned long length, bytesAfter;
+	Atom actualType, propName;
+	char *property, **propertyPtr = &property, *p, *end;
+	Window w;
+
+	if ((objc != 4) && (objc != 5)) {
+		Tcl_WrongNumArgs(interp, 1, objv,
+			"prop window name ?value ?");
+	    return TCL_ERROR;
+	}
+	if (strcmp(Tcl_GetString(objv[2]), "root") == 0) {
+	    w = RootWindow(winPtr->dispPtr->display, 0);
+	} else if (strcmp(Tcl_GetString(objv[2]), "comm") == 0) {
+	    w = Tk_WindowId(winPtr->dispPtr->commTkwin);
+	} else {
+	    w = strtoul(Tcl_GetString(objv[2]), &end, 0);
+	}
+	propName = Tk_InternAtom((Tk_Window) winPtr, Tcl_GetString(objv[3]));
+	if (objc == 4) {
+	    property = NULL;
+	    result = XGetWindowProperty(winPtr->dispPtr->display, w, propName,
+		    0, 100000, False, XA_STRING, &actualType, &actualFormat,
+		    &length, &bytesAfter, (unsigned char **) propertyPtr);
+	    if ((result == Success) && (actualType != None)
+		    && (actualFormat == 8) && (actualType == XA_STRING)) {
+		for (p = property; (unsigned long)(p-property) < length; p++) {
+		    if (*p == 0) {
+			*p = '\n';
+		    }
+		}
+		Tcl_SetObjResult(interp, Tcl_NewStringObj(property, -1));
+	    }
+	    if (property != NULL) {
+		XFree(property);
+	    }
+	} else if (Tcl_GetString(objv[4])[0] == 0) {
+	    XDeleteProperty(winPtr->dispPtr->display, w, propName);
+	} else {
+	    Tcl_DString tmp;
+
+	    Tcl_DStringInit(&tmp);
+	    for (p = Tcl_DStringAppend(&tmp, Tcl_GetString(objv[4]),
+		    (int) strlen(Tcl_GetString(objv[4]))); *p != 0; p++) {
+		if (*p == '\n') {
+		    *p = 0;
+		}
+	    }
+
+	    XChangeProperty(winPtr->dispPtr->display, w, propName, XA_STRING,
+		    8, PropModeReplace, (unsigned char*)Tcl_DStringValue(&tmp),
+		    p-Tcl_DStringValue(&tmp));
+	    Tcl_DStringFree(&tmp);
+	}
+    } else if (index == TESTSEND_SERIAL) {
+	Tcl_SetObjResult(interp, Tcl_NewIntObj(localData.sendSerial+1));
+    }
+    return TCL_OK;
+}
+
+/*
+ * Local Variables:
+ * mode: c
+ * c-basic-offset: 4
+ * fill-column: 78
+ * End:
+ */