Check in new file for select tests

* tests/select_helper_multiple.c: New file.

tests/select_helper_multiple.c

@@ -0,0 +1,245 @@
+/* Tests for the Wayland compositor running on the X server.
+
+Copyright (C) 2022 to various contributors.
+
+This file is part of 12to11.
+
+12to11 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.
+
+12to11 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 12to11.  If not, see <https://www.gnu.org/licenses/>.  */
+
+#include <stdbool.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+
+#include <X11/Xlib.h>
+#include <X11/Xatom.h>
+
+/* select_helper_multiple.c -- Perform a request for multiple
+   selections.
+
+   There must be at least three arguments: the name of the display,
+   the timestamp at which the selection was acquired, and the
+   target(s).  */
+
+/* The display connected to.  */
+static Display *display;
+
+/* The selection transfer window.  */
+static Window selection_transfer_window;
+
+/* Various atoms.  */
+static Atom CLIPBOARD, INCR, MULTIPLE, ATOM_PAIR, *target_atoms;
+
+static void
+wait_for_selection_notify (XEvent *event)
+{
+  while (true)
+    {
+      XNextEvent (display, event);
+
+      if (event->type == SelectionNotify
+	  && (event->xselection.requestor
+	      == selection_transfer_window)
+	  && (event->xselection.selection
+	      == CLIPBOARD)
+	  && (event->xselection.property
+	      == MULTIPLE)
+	  && (event->xselection.target
+	      == MULTIPLE))
+	return;
+    }
+}
+
+static void
+wait_for_new_value (XEvent *event, Atom property)
+{
+  while (true)
+    {
+      XNextEvent (display, event);
+
+      if (event->type == PropertyNotify
+	  && event->xproperty.atom == property
+	  && event->xproperty.state == PropertyNewValue)
+	return;
+    }
+}
+
+static size_t
+get_size_for_format (int format)
+{
+  switch (format)
+    {
+    case 32:
+      return sizeof (long);
+
+    case 16:
+      return sizeof (short int);
+
+    case 8:
+      return sizeof (char);
+    }
+
+  /* Should not actually happen.  */
+  return 0;
+}
+
+int
+main (int argc, char **argv)
+{
+  XSetWindowAttributes attrs;
+  unsigned long flags, timestamp;
+  char *atom_names[4];
+  Atom atoms[4], actual_type, property, *parameters;
+  XEvent event;
+  int actual_format, i;
+  unsigned long nitems, bytes_after;
+  unsigned char *data;
+
+  if (argc < 4)
+    /* Not enough arguments were specified.  */
+    return 1;
+
+  display = XOpenDisplay (argv[1]);
+
+  if (!display)
+    return 1;
+
+  /* Make the window used to transfer selection data.  */
+  attrs.override_redirect = True;
+  attrs.event_mask = PropertyChangeMask;
+  flags = CWEventMask | CWOverrideRedirect;
+
+  selection_transfer_window
+    = XCreateWindow (display, DefaultRootWindow (display),
+		     -1, -1, 1, 1, 0, CopyFromParent, InputOnly,
+		     CopyFromParent, flags, &attrs);
+
+  /* Get the time.  */
+  timestamp = strtoul (argv[2], NULL, 10);
+
+  atom_names[0] = (char *) "CLIPBOARD";
+  atom_names[1] = (char *) "INCR";
+  atom_names[2] = (char *) "MULTIPLE";
+  atom_names[3] = (char *) "ATOM_PAIR";
+  XInternAtoms (display, atom_names, 4, False, atoms);
+  CLIPBOARD = atoms[0];
+  INCR = atoms[1];
+  MULTIPLE = atoms[2];
+  ATOM_PAIR = atoms[3];
+
+  /* Intern the target atoms.  */
+  target_atoms = malloc (sizeof *target_atoms * argc - 3);
+  XInternAtoms (display, &argv[3], argc - 3, False, target_atoms);
+
+  /* Write each of the atoms as parameters before making the selection
+     request.  */
+  atoms[0] = target_atoms[0];
+  atoms[1] = target_atoms[0];
+  XChangeProperty (display, selection_transfer_window, MULTIPLE,
+		   ATOM_PAIR, 32, PropModeReplace,
+		   (unsigned char *) atoms, 2);
+
+  for (i = 1; i < argc - 3; ++i)
+    {
+      atoms[0] = target_atoms[i];
+      atoms[1] = target_atoms[i];
+      XChangeProperty (display, selection_transfer_window, MULTIPLE,
+		       ATOM_PAIR, 32, PropModeAppend,
+		       (unsigned char *) atoms, 2);
+    }
+
+  /* Now, request the selection.  */
+  XConvertSelection (display, CLIPBOARD, MULTIPLE,
+		     MULTIPLE, selection_transfer_window,
+		     timestamp);
+
+  /* And wait for the SelectionNotify event.  */
+  wait_for_selection_notify (&event);
+
+  /* Selection conversion failed.  */
+  if (event.xselection.property == None)
+    return 1;
+
+  /* Now, read the MULTIPLE property again.  See which conversions
+     were completed.  */
+  XGetWindowProperty (display, selection_transfer_window,
+		      event.xselection.property, 0, (argc - 3) * 2,
+		      True, ATOM_PAIR,
+		      &actual_type, &actual_format, &nitems,
+		      &bytes_after, &data);
+
+  if (actual_format != 32 || actual_type != ATOM_PAIR
+      || nitems != (argc - 3) * 2)
+    return 1;
+
+  parameters = (Atom *) data;
+
+  for (i = 0; i < argc - 3; ++i)
+    {
+      if (!parameters[i * 2 + 1])
+	continue;
+
+      property = parameters[i * 2];
+
+      XGetWindowProperty (display, selection_transfer_window,
+			  property, 0, 0xffffffff, True, AnyPropertyType,
+			  &actual_type, &actual_format, &nitems, &bytes_after,
+			  &data);
+
+      if (!data || bytes_after)
+	return 1;
+
+      if (actual_type == INCR)
+	{
+	  while (true)
+	    {
+	      XFree (data);
+
+	      wait_for_new_value (&event, property);
+	      XGetWindowProperty (display, selection_transfer_window, property, 0,
+				  0xffffffff, True, AnyPropertyType, &actual_type,
+				  &actual_format, &nitems, &bytes_after, &data);
+
+	      if (!data)
+		return 0;
+
+	      if (nitems)
+		{
+		  /* Write the selection data to stdout.  */
+		  if (fwrite (data, get_size_for_format (actual_format),
+			      nitems, stdout) != nitems)
+		    return 1;
+
+		  continue;
+		}
+
+	      /* Selection transfer is complete.  */
+	      fflush (stdout);
+	      break;
+	    }
+	}
+      else
+	{
+	  /* Write the selection data to stdout.  */
+	  if (fwrite (data, get_size_for_format (actual_format),
+		      nitems, stdout) != nitems)
+	    return 1;
+
+	  /* Return success.  */
+	  fflush (stdout);
+	}
+    }
+
+  return 0;
+}