Adding upstream version 3:4.8.29.upstream/3%4.8.29upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 262 insertions, 0 deletions

diff --git a/lib/tty/x11conn.c b/lib/tty/x11conn.c
new file mode 100644
index 0000000..68e83b4
--- /dev/null
+++ b/lib/tty/x11conn.c
@@ -0,0 +1,262 @@
+/*
+   X11 support for the Midnight Commander.
+
+   Copyright (C) 2005-2022
+   Free Software Foundation, Inc.
+
+   Written by:
+   Roland Illig <roland.illig@gmx.de>, 2005.
+
+   This file is part of the Midnight Commander.
+
+   The Midnight Commander is free software: you can redistribute it
+   and/or modify it under the terms of the GNU General Public License as
+   published by the Free Software Foundation, either version 3 of the License,
+   or (at your option) any later version.
+
+   The Midnight Commander is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/** \file x11conn.c
+ *  \brief Source: X11 support
+ *  \warning This code uses setjmp() and longjmp(). Before you modify _anything_ here,
+ *  please read the relevant sections of the C standard.
+ */
+
+#include <config.h>
+
+#include <setjmp.h>
+#include <X11/Xlib.h>
+#ifdef HAVE_GMODULE
+#include <gmodule.h>
+#endif
+
+#include "lib/global.h"
+#include "x11conn.h"
+
+/*** global variables ****************************************************************************/
+
+/*** file scope macro definitions ****************************************************************/
+
+#ifndef HAVE_GMODULE
+#define func_XOpenDisplay       XOpenDisplay
+#define func_XCloseDisplay      XCloseDisplay
+#define func_XSetErrorHandler   XSetErrorHandler
+#define func_XSetIOErrorHandler XSetIOErrorHandler
+#define func_XQueryPointer      XQueryPointer
+#endif
+
+/*** file scope type declarations ****************************************************************/
+
+typedef int (*mc_XErrorHandler_callback) (Display *, XErrorEvent *);
+typedef int (*mc_XIOErrorHandler_callback) (Display *);
+
+/*** file scope variables ************************************************************************/
+
+#ifdef HAVE_GMODULE
+static Display *(*func_XOpenDisplay) (_Xconst char *);
+static int (*func_XCloseDisplay) (Display *);
+static mc_XErrorHandler_callback (*func_XSetErrorHandler) (mc_XErrorHandler_callback);
+static mc_XIOErrorHandler_callback (*func_XSetIOErrorHandler) (mc_XIOErrorHandler_callback);
+static Bool (*func_XQueryPointer) (Display *, Window, Window *, Window *,
+                                   int *, int *, int *, int *, unsigned int *);
+static GModule *x11_module;
+#endif
+
+static gboolean handlers_installed = FALSE;
+
+/* This flag is set as soon as an X11 error is reported. Usually that
+ * means that the DISPLAY is not available anymore. We do not try to
+ * reconnect, as that would violate the X11 protocol. */
+static gboolean lost_connection = FALSE;
+
+static jmp_buf x11_exception;   /* FIXME: get a better name */
+static gboolean longjmp_allowed = FALSE;
+
+/*** file scope functions ************************************************************************/
+/* --------------------------------------------------------------------------------------------- */
+
+static int
+x_io_error_handler (Display * dpy)
+{
+    (void) dpy;
+
+    lost_connection = TRUE;
+    if (longjmp_allowed)
+    {
+        longjmp_allowed = FALSE;
+        longjmp (x11_exception, 1);
+    }
+    return 0;
+}
+
+/* --------------------------------------------------------------------------------------------- */
+
+static int
+x_error_handler (Display * dpy, XErrorEvent * ee)
+{
+    (void) ee;
+    (void) func_XCloseDisplay (dpy);
+    return x_io_error_handler (dpy);
+}
+
+/* --------------------------------------------------------------------------------------------- */
+
+static void
+install_error_handlers (void)
+{
+    if (handlers_installed)
+        return;
+
+    (void) func_XSetErrorHandler (x_error_handler);
+    (void) func_XSetIOErrorHandler (x_io_error_handler);
+    handlers_installed = TRUE;
+}
+
+/* --------------------------------------------------------------------------------------------- */
+
+static gboolean
+x11_available (void)
+{
+#ifdef HAVE_GMODULE
+    gchar *x11_module_fname;
+
+    if (lost_connection)
+        return FALSE;
+
+    if (x11_module != NULL)
+        return TRUE;
+
+    x11_module_fname = g_module_build_path (NULL, "X11");
+    x11_module = g_module_open (x11_module_fname, G_MODULE_BIND_LAZY);
+    if (x11_module == NULL)
+        x11_module = g_module_open ("libX11.so.6", G_MODULE_BIND_LAZY);
+
+    g_free (x11_module_fname);
+
+    if (x11_module == NULL)
+        return FALSE;
+
+    if (!g_module_symbol (x11_module, "XOpenDisplay", (void *) &func_XOpenDisplay))
+        goto cleanup;
+    if (!g_module_symbol (x11_module, "XCloseDisplay", (void *) &func_XCloseDisplay))
+        goto cleanup;
+    if (!g_module_symbol (x11_module, "XQueryPointer", (void *) &func_XQueryPointer))
+        goto cleanup;
+    if (!g_module_symbol (x11_module, "XSetErrorHandler", (void *) &func_XSetErrorHandler))
+        goto cleanup;
+    if (!g_module_symbol (x11_module, "XSetIOErrorHandler", (void *) &func_XSetIOErrorHandler))
+        goto cleanup;
+
+    install_error_handlers ();
+    return TRUE;
+
+  cleanup:
+    func_XOpenDisplay = 0;
+    func_XCloseDisplay = 0;
+    func_XQueryPointer = 0;
+    func_XSetErrorHandler = 0;
+    func_XSetIOErrorHandler = 0;
+    g_module_close (x11_module);
+    x11_module = NULL;
+    return FALSE;
+#else
+    install_error_handlers ();
+    return !(lost_connection);
+#endif
+}
+
+/* --------------------------------------------------------------------------------------------- */
+/*** public functions ****************************************************************************/
+/* --------------------------------------------------------------------------------------------- */
+
+Display *
+mc_XOpenDisplay (const char *displayname)
+{
+    if (x11_available ())
+    {
+        if (setjmp (x11_exception) == 0)
+        {
+            Display *retval;
+
+            /* cppcheck-suppress redundantAssignment */
+            longjmp_allowed = TRUE;
+
+            retval = func_XOpenDisplay (displayname);
+
+            /* cppcheck-suppress redundantAssignment */
+            longjmp_allowed = FALSE;
+            return retval;
+        }
+    }
+    return NULL;
+}
+
+/* --------------------------------------------------------------------------------------------- */
+
+int
+mc_XCloseDisplay (Display * display)
+{
+    if (x11_available ())
+    {
+        if (setjmp (x11_exception) == 0)
+        {
+            int retval;
+
+            /* cppcheck-suppress redundantAssignment */
+            longjmp_allowed = TRUE;
+
+            retval = func_XCloseDisplay (display);
+
+            /* cppcheck-suppress redundantAssignment */
+            longjmp_allowed = FALSE;
+
+            return retval;
+        }
+    }
+    return 0;
+}
+
+/* --------------------------------------------------------------------------------------------- */
+
+Bool
+mc_XQueryPointer (Display * display, Window win, Window * root_return,
+                  Window * child_return, int *root_x_return, int *root_y_return,
+                  int *win_x_return, int *win_y_return, unsigned int *mask_return)
+{
+    Bool retval;
+
+    if (x11_available ())
+    {
+        if (setjmp (x11_exception) == 0)
+        {
+            /* cppcheck-suppress redundantAssignment */
+            longjmp_allowed = TRUE;
+
+            retval = func_XQueryPointer (display, win, root_return,
+                                         child_return, root_x_return, root_y_return,
+                                         win_x_return, win_y_return, mask_return);
+
+            /* cppcheck-suppress redundantAssignment */
+            longjmp_allowed = FALSE;
+
+            return retval;
+        }
+    }
+    *root_return = None;
+    *child_return = None;
+    *root_x_return = 0;
+    *root_y_return = 0;
+    *win_x_return = 0;
+    *win_y_return = 0;
+    *mask_return = 0;
+    return False;
+}
+
+/* --------------------------------------------------------------------------------------------- */