Fix a crash when parsing an invalid color sequence (reported by Kuang-che Wu).

1 files changed, 1279 insertions, 0 deletions

diff --git a/src/rxvttoolkit.C b/src/rxvttoolkit.C
new file mode 100644
index 0000000..d92c5b9
--- /dev/null
+++ b/src/rxvttoolkit.C
@@ -0,0 +1,1279 @@
+/*----------------------------------------------------------------------*
+ * File:	rxvttoolkit.C
+ *----------------------------------------------------------------------*
+ *
+ * All portions of code are copyright by their respective author/s.
+ * Copyright (c) 2003-2011 Marc Lehmann <schmorp@schmorp.de>
+ * Copyright (c) 2011      Emanuele Giaquinta <e.giaquinta@glauco.it>
+ *
+ * This program 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.
+ *
+ * This program 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, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *----------------------------------------------------------------------*/
+
+#include "../config.h"
+#include <rxvt.h>
+#include <rxvttoolkit.h>
+
+#include <stdlib.h>
+
+#include <unistd.h>
+#include <fcntl.h>
+
+#include <sys/utsname.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+
+#if XFT
+# include <X11/extensions/Xrender.h>
+#endif
+
+static const char *const xa_names[] =
+{
+  "TEXT",
+  "COMPOUND_TEXT",
+  "UTF8_STRING",
+  "MULTIPLE",
+  "TARGETS",
+  "TIMESTAMP",
+  "VT_SELECTION",
+  "INCR",
+  "WM_PROTOCOLS",
+  "WM_DELETE_WINDOW",
+  "CLIPBOARD",
+  "AVERAGE_WIDTH",
+  "WEIGHT_NAME",
+  "SLANT",
+  "CHARSET_REGISTRY",
+  "CHARSET_ENCODING",
+#if ENABLE_FRILLS
+  "_MOTIF_WM_HINTS",
+#endif
+#if ENABLE_EWMH
+  "_NET_WM_PID",
+  "_NET_WM_NAME",
+  "_NET_WM_ICON_NAME",
+  "_NET_WM_PING",
+  "_NET_WM_ICON",
+#endif
+#if USE_XIM
+  "WM_LOCALE_NAME",
+  "XIM_SERVERS",
+#endif
+#if HAVE_IMG || ENABLE_PERL
+  "_XROOTPMAP_ID",
+  "ESETROOT_PMAP_ID",
+#endif
+#if ENABLE_XEMBED
+  "_XEMBED",
+  "_XEMBED_INFO",
+#endif
+#if !ENABLE_MINIMAL
+  "SCREEN_RESOURCES",
+  "XDCCC_LINEAR_RGB_CORRECTION",
+  "XDCCC_LINEAR_RGB_MATRICES",
+  "WM_COLORMAP_WINDOWS",
+  "WM_STATE",
+  "cursor",
+# if USE_XIM
+  "TRANSPORT",
+  "LOCALES",
+  "_XIM_PROTOCOL",
+  "_XIM_XCONNECT",
+  "_XIM_MOREDATA",
+# endif
+#endif
+};
+
+/////////////////////////////////////////////////////////////////////////////
+
+refcounted::refcounted (const char *id)
+{
+  this->id = strdup (id);
+}
+
+refcounted::~refcounted ()
+{
+  free (id);
+}
+
+template<class T>
+T *refcache<T>::get (const char *id)
+{
+  for (T **i = this->begin (); i < this->end (); ++i)
+    {
+      if (!strcmp (id, (*i)->id))
+        {
+          ++(*i)->referenced;
+          (*i)->ref_next ();
+          return *i;
+        }
+    }
+
+  T *obj = new T (id);
+
+  if (obj && obj->ref_init ())
+    {
+      obj->referenced = 1;
+      this->push_back (obj);
+      return obj;
+    }
+  else
+    {
+      delete obj;
+      return 0;
+    }
+}
+
+template<class T>
+void refcache<T>::put (T *obj)
+{
+  if (!obj)
+    return;
+
+  if (!--obj->referenced)
+    {
+      this->erase (find (this->begin (), this->end (), obj));
+      delete obj;
+    }
+}
+
+template<class T>
+void refcache<T>::clear ()
+{
+  while (this->size ())
+    put (*this->begin ());
+}
+
+/////////////////////////////////////////////////////////////////////////////
+
+#if USE_XIM
+
+static void
+#if XIMCB_PROTO_BROKEN
+im_destroy_cb (XIC unused1, XPointer client_data, XPointer unused3)
+#else
+im_destroy_cb (XIM unused1, XPointer client_data, XPointer unused3)
+#endif
+{
+  rxvt_xim *xim = (rxvt_xim *)client_data;
+  rxvt_display *display = xim->display;
+
+  xim->xim = 0;
+
+  display->xims.erase (find (display->xims.begin (), display->xims.end (), xim));
+  display->im_change_cb ();
+}
+
+bool
+rxvt_xim::ref_init ()
+{
+  display = GET_R->display; //HACK: TODO
+
+  xim = XOpenIM (display->dpy, 0, 0, 0);
+
+  if (!xim)
+    return false;
+
+  XIMCallback ximcallback;
+  ximcallback.client_data = (XPointer)this;
+  ximcallback.callback = im_destroy_cb;
+
+  XSetIMValues (xim, XNDestroyCallback, &ximcallback, (char *)0);
+
+  return true;
+}
+
+rxvt_xim::~rxvt_xim ()
+{
+  if (xim)
+    XCloseIM (xim);
+}
+
+#endif
+
+/////////////////////////////////////////////////////////////////////////////
+
+#if XFT
+rxvt_drawable::~rxvt_drawable ()
+{
+  if (xftdrawable)
+    XftDrawDestroy (xftdrawable);
+}
+
+rxvt_drawable::operator XftDraw *()
+{
+  if (!xftdrawable)
+    xftdrawable = XftDrawCreate (screen->dpy, drawable, screen->visual, screen->cmap);
+
+  return xftdrawable;
+}
+#endif
+
+/////////////////////////////////////////////////////////////////////////////
+
+#if XFT
+
+// not strictly necessary as it is only used with superclass of zero_initialised
+rxvt_screen::rxvt_screen ()
+: scratch_area (0)
+{
+}
+
+rxvt_drawable &rxvt_screen::scratch_drawable (int w, int h)
+{
+  if (!scratch_area || w > scratch_w || h > scratch_h)
+    {
+      if (scratch_area)
+        {
+          XFreePixmap (dpy, scratch_area->drawable);
+          delete scratch_area;
+        }
+
+      Pixmap pm = XCreatePixmap (dpy, RootWindowOfScreen (ScreenOfDisplay (dpy, display->screen)),
+                                 scratch_w = w, scratch_h = h, depth);
+
+      scratch_area = new rxvt_drawable (this, pm);
+    }
+
+  return *scratch_area;
+}
+
+#endif
+
+void
+rxvt_screen::set (rxvt_display *disp)
+{
+  display = disp;
+  dpy     = disp->dpy;
+
+  Screen *screen = ScreenOfDisplay (dpy, disp->screen);
+
+  depth   = DefaultDepthOfScreen    (screen);
+  visual  = DefaultVisualOfScreen   (screen);
+  cmap    = DefaultColormapOfScreen (screen);
+}
+
+#if ENABLE_FRILLS
+
+void
+rxvt_screen::select_visual (int id)
+{
+  XVisualInfo vinfo;
+  vinfo.visualid = id;
+  int n;
+
+  if (XVisualInfo *vi = XGetVisualInfo (dpy, VisualIDMask, &vinfo, &n))
+    {
+      depth  = vi->depth;
+      visual = vi->visual;
+
+      XFree (vi);
+
+      cmap = XCreateColormap (dpy, display->root, visual, AllocNone);
+    }
+  else
+    rxvt_warn ("no visual found for requested id 0x%02x, using default visual.\n", id);
+}
+
+void
+rxvt_screen::select_depth (int bitdepth)
+{
+  XVisualInfo vinfo;
+
+  if (XMatchVisualInfo (dpy, display->screen, bitdepth, TrueColor, &vinfo))
+    select_visual (vinfo.visualid);
+  else
+    rxvt_warn ("no visual found for requested depth %d, using default visual.\n", bitdepth);
+}
+
+#endif
+
+void
+rxvt_screen::clear ()
+{
+#if XFT
+  if (scratch_area)
+    {
+      XFreePixmap (dpy, scratch_area->drawable);
+      delete scratch_area;
+    }
+#endif
+
+  if (cmap != DefaultColormapOfScreen (ScreenOfDisplay (dpy, display->screen)))
+    XFreeColormap (dpy, cmap);
+}
+
+/////////////////////////////////////////////////////////////////////////////
+
+rxvt_display::rxvt_display (const char *id)
+: refcounted (id)
+, selection_owner (0)
+, clipboard_owner (0)
+{
+  x_ev    .set<rxvt_display, &rxvt_display::x_cb    > (this);
+  flush_ev.set<rxvt_display, &rxvt_display::flush_cb> (this);
+}
+
+XrmDatabase
+rxvt_display::get_resources (bool refresh)
+{
+  char *homedir = getenv ("HOME");
+  char fname[1024];
+
+  /*
+   * get resources using the X library function
+   */
+  char *displayResource, *xe;
+  XrmDatabase rdb1, database = 0;
+
+#if !XLIB_ILLEGAL_ACCESS
+  /* work around a bug in XrmSetDatabase where it frees the db, see ref_next */
+  database = XrmGetStringDatabase ("");
+#endif
+
+  // for ordering, see for example http://www.faqs.org/faqs/Xt-FAQ/ Subject: 20
+  // as opposed to "standard practise", we always read in ~/.Xdefaults
+
+  // 6. System wide per application default file.
+
+  /* Add in $XAPPLRESDIR/Rxvt only; not bothering with XUSERFILESEARCHPATH */
+  if ((xe = getenv ("XAPPLRESDIR")))
+    {
+      snprintf (fname, sizeof (fname), "%s/%s", xe, RESCLASS);
+
+      if ((rdb1 = XrmGetFileDatabase (fname)))
+        XrmMergeDatabases (rdb1, &database);
+    }
+
+  // 5. User's per application default file.
+  // none
+
+  // 4. User's defaults file.
+  if (homedir)
+    {
+      snprintf (fname, sizeof (fname), "%s/.Xdefaults", homedir);
+
+      if ((rdb1 = XrmGetFileDatabase (fname)))
+        XrmMergeDatabases (rdb1, &database);
+    }
+
+  /* Get any Xserver defaults */
+  if (refresh)
+    {
+      // fucking xlib keeps a copy of the rm string
+      Atom actual_type;
+      int actual_format;
+      unsigned long nitems, nremaining;
+      char *val = 0;
+
+#if XLIB_ILLEGAL_ACCESS
+      if (dpy->xdefaults)
+        XFree (dpy->xdefaults);
+#endif
+
+      if (XGetWindowProperty (dpy, RootWindow (dpy, 0), XA_RESOURCE_MANAGER,
+                              0L, 100000000L, False,
+                              XA_STRING, &actual_type, &actual_format,
+                              &nitems, &nremaining,
+                              (unsigned char **)&val) == Success
+          && actual_type == XA_STRING
+          && actual_format == 8)
+        displayResource = val;
+      else
+        {
+          displayResource = 0;
+
+          if (val)
+            XFree (val);
+        }
+
+#if XLIB_ILLEGAL_ACCESS
+      dpy->xdefaults = displayResource;
+#endif
+    }
+  else
+    displayResource = XResourceManagerString (dpy);
+
+  if (displayResource)
+    {
+      if ((rdb1 = XrmGetStringDatabase (displayResource)))
+        XrmMergeDatabases (rdb1, &database);
+    }
+
+#if !XLIB_ILLEGAL_ACCESS
+  if (refresh && displayResource)
+    XFree (displayResource);
+#endif
+
+  /* Get screen specific resources */
+  displayResource = XScreenResourceString (ScreenOfDisplay (dpy, screen));
+
+  if (displayResource)
+    {
+      if ((rdb1 = XrmGetStringDatabase (displayResource)))
+        /* Merge with screen-independent resources */
+        XrmMergeDatabases (rdb1, &database);
+
+      XFree (displayResource);
+    }
+
+  // 3. User's per host defaults file
+  /* Add in XENVIRONMENT file */
+  if ((xe = getenv ("XENVIRONMENT"))
+      && (rdb1 = XrmGetFileDatabase (xe)))
+    XrmMergeDatabases (rdb1, &database);
+  else if (homedir)
+    {
+      struct utsname un;
+
+      if (!uname (&un))
+        {
+          snprintf (fname, sizeof (fname), "%s/.Xdefaults-%s", homedir, un.nodename);
+
+          if ((rdb1 = XrmGetFileDatabase (fname)))
+            XrmMergeDatabases (rdb1, &database);
+        }
+    }
+
+  return database;
+}
+
+bool rxvt_display::ref_init ()
+{
+#ifdef LOCAL_X_IS_UNIX
+  if (id[0] == ':')
+    {
+      char *val = rxvt_temp_buf<char> (5 + strlen (id) + 1);
+
+      strcpy (val, "unix/");
+      strcat (val, id);
+
+      dpy = XOpenDisplay (val);
+    }
+  else
+#endif
+    dpy = 0;
+
+  if (!dpy)
+    dpy = XOpenDisplay (id);
+
+  if (!dpy)
+    return false;
+
+  screen = DefaultScreen     (dpy);
+  root   = DefaultRootWindow (dpy);
+
+  assert (ecb_array_length (xa_names) == NUM_XA);
+  XInternAtoms (dpy, (char **)xa_names, NUM_XA, False, xa);
+
+  XrmSetDatabase (dpy, get_resources (false));
+
+#ifdef POINTER_BLANK
+  XColor blackcolour;
+  blackcolour.red   = 0;
+  blackcolour.green = 0;
+  blackcolour.blue  = 0;
+  Font f = XLoadFont (dpy, "fixed");
+  blank_cursor = XCreateGlyphCursor (dpy, f, f, ' ', ' ',
+                                     &blackcolour, &blackcolour);
+  XUnloadFont (dpy, f);
+#endif
+
+  flags = 0;
+#if XRENDER
+  int major, minor;
+  if (XRenderQueryVersion (dpy, &major, &minor))
+    if (major > 0 || (major == 0 && minor >= 11))
+      {
+        flags |= DISPLAY_HAS_RENDER;
+
+        if (XFilters *filters = XRenderQueryFilters (dpy, root))
+          {
+            for (int i = 0; i < filters->nfilter; i++)
+              if (!strcmp (filters->filter [i], FilterConvolution))
+                flags |= DISPLAY_HAS_RENDER_CONV;
+
+            XFree (filters);
+          }
+      }
+#endif
+
+  int fd = XConnectionNumber (dpy);
+
+  // try to detect whether we have a local connection.
+  // assume unix domain socket == local, everything else not
+  // TODO: might want to check for inet/127.0.0.1
+  is_local = 0;
+  sockaddr_un sa;
+  socklen_t sl = sizeof (sa);
+
+  if (!getsockname (fd, (sockaddr *)&sa, &sl))
+    is_local = sa.sun_family == AF_UNIX;
+
+  flush_ev.start ();
+  x_ev.start (fd, ev::READ);
+  fcntl (fd, F_SETFD, FD_CLOEXEC);
+
+  XSelectInput (dpy, root, PropertyChangeMask);
+
+  flush ();
+
+  return true;
+}
+
+void
+rxvt_display::ref_next ()
+{
+  // TODO: somehow check whether the database files/resources changed
+  // before affording re-loading/parsing
+  XrmDestroyDatabase (XrmGetDatabase (dpy));
+#if XLIB_ILLEGAL_ACCESS
+  /* work around a bug in XrmSetDatabase where it frees the db */
+  dpy->db = 0;
+#endif
+  XrmSetDatabase (dpy, get_resources (true));
+}
+
+rxvt_display::~rxvt_display ()
+{
+  if (!dpy)
+    return;
+
+#ifdef POINTER_BLANK
+  XFreeCursor (dpy, blank_cursor);
+#endif
+  x_ev.stop ();
+  flush_ev.stop ();
+#if USE_XIM
+  xims.clear ();
+#endif
+  XrmDestroyDatabase (XrmGetDatabase (dpy));
+  XCloseDisplay (dpy);
+}
+
+#if USE_XIM
+void rxvt_display::im_change_cb ()
+{
+  for (im_watcher **i = imw.begin (); i != imw.end (); ++i)
+    (*i)->call ();
+}
+
+void rxvt_display::im_change_check ()
+{
+  // try to only call im_change_cb when a new input method
+  // registers, as xlib crashes due to a race otherwise.
+  Atom actual_type, *atoms;
+  int actual_format;
+  unsigned long nitems, bytes_after;
+
+  if (XGetWindowProperty (dpy, root, xa[XA_XIM_SERVERS], 0L, 1000000L,
+                          False, XA_ATOM, &actual_type, &actual_format,
+                          &nitems, &bytes_after, (unsigned char **)&atoms)
+      != Success)
+    return;
+
+  if (actual_type == XA_ATOM && actual_format == 32)
+    for (int i = 0; i < nitems; i++)
+      if (XGetSelectionOwner (dpy, atoms[i]))
+        {
+          im_change_cb ();
+          break;
+        }
+
+  XFree (atoms);
+}
+#endif
+
+void rxvt_display::x_cb (ev::io &w, int revents)
+{
+  flush_ev.start ();
+}
+
+void rxvt_display::flush_cb (ev::prepare &w, int revents)
+{
+  while (XEventsQueued (dpy, QueuedAfterFlush))
+    do
+      {
+        XEvent xev;
+        XNextEvent (dpy, &xev);
+
+#if USE_XIM
+        if (!XFilterEvent (&xev, None))
+          {
+            if (xev.type == PropertyNotify
+                && xev.xany.window == root
+                && xev.xproperty.atom == xa[XA_XIM_SERVERS])
+              im_change_check ();
+#endif
+            if (xev.type == MappingNotify)
+              XRefreshKeyboardMapping (&xev.xmapping);
+
+            for (int i = xw.size (); i--; )
+              {
+                if (!xw[i])
+                  xw.erase_unordered (i);
+                else if (xw[i]->window == xev.xany.window)
+                  xw[i]->call (xev);
+              }
+#if USE_XIM
+          }
+#endif
+      }
+    while (XEventsQueued (dpy, QueuedAlready));
+
+  w.stop ();
+}
+
+void rxvt_display::reg (xevent_watcher *w)
+{
+  if (!w->active)
+    {
+      xw.push_back (w);
+      w->active = xw.size ();
+    }
+}
+
+void rxvt_display::unreg (xevent_watcher *w)
+{
+  if (w->active)
+    {
+      xw[w->active - 1] = 0;
+      w->active = 0;
+    }
+}
+
+void rxvt_display::set_selection_owner (rxvt_term *owner, bool clipboard)
+{
+  rxvt_term * &cur_owner = !clipboard ? selection_owner : clipboard_owner;
+
+  if (cur_owner && cur_owner != owner)
+    {
+      rxvt_term *term = cur_owner;
+      term->selection_clear (clipboard);
+      term->flush ();
+    }
+
+  cur_owner = owner;
+}
+
+#if USE_XIM
+
+void rxvt_display::reg (im_watcher *w)
+{
+  imw.push_back (w);
+}
+
+void rxvt_display::unreg (im_watcher *w)
+{
+  imw.erase (find (imw.begin (), imw.end (), w));
+}
+
+rxvt_xim *rxvt_display::get_xim (const char *locale, const char *modifiers)
+{
+  char *id;
+  int l, m;
+
+  l = strlen (locale);
+  m = strlen (modifiers);
+
+  if (!(id = rxvt_temp_buf<char> (l + m + 2)))
+    return 0;
+
+  memcpy (id, locale, l); id[l] = '\n';
+  memcpy (id + l + 1, modifiers, m); id[l + m + 1] = 0;
+
+  rxvt_xim *xim = xims.get (id);
+
+  return xim;
+}
+
+void rxvt_display::put_xim (rxvt_xim *xim)
+{
+# if XLIB_IS_RACEFREE
+  xims.put (xim);
+# endif
+}
+
+#endif
+
+Atom rxvt_display::atom (const char *name)
+{
+  return XInternAtom (dpy, name, False);
+}
+
+Pixmap
+rxvt_display::get_pixmap_property (Atom property)
+{
+  Pixmap pixmap = None;
+
+  int aformat;
+  unsigned long nitems, bytes_after;
+  Atom atype;
+  unsigned char *prop;
+  int result = XGetWindowProperty (dpy, root, property,
+                                   0L, 1L, False, XA_PIXMAP, &atype, &aformat,
+                                   &nitems, &bytes_after, &prop);
+  if (result == Success)
+    {
+      if (atype == XA_PIXMAP)
+        pixmap = *(Pixmap *)prop;
+      XFree (prop);
+    }
+
+  return pixmap;
+}
+
+/////////////////////////////////////////////////////////////////////////////
+
+template class refcache<rxvt_display>;
+refcache<rxvt_display> displays;
+
+/////////////////////////////////////////////////////////////////////////////
+//
+
+static unsigned int
+insert_component (unsigned int value, unsigned int mask, unsigned int shift)
+{
+  return (value * (mask + 1) >> 16) << shift;
+}
+
+bool
+rxvt_color::alloc (rxvt_screen *screen, const rgba &color)
+{
+  //TODO: only supports 24 bit
+  unsigned int alpha = color.a >= 0xff00 ? 0xffff : color.a;
+
+#if XFT
+  XRenderPictFormat *format;
+
+  // not needed by XftColorAlloc, but by the other paths (ours
+  // and fallback), so just set all components here.
+  c.color.red   = color.r;
+  c.color.green = color.g;
+  c.color.blue  = color.b;
+  c.color.alpha = alpha;
+
+  // FUCKING Xft gets it wrong, of course, so work around it.
+  // Transparency users should eat shit and die, and then
+  // XRenderQueryPictIndexValues themselves plenty.
+  if ((screen->visual->c_class == TrueColor)
+      && (format = XRenderFindVisualFormat (screen->dpy, screen->visual)))
+    {
+      // the fun lies in doing everything manually...
+
+      // Xft wants premultiplied alpha, but abuses the alpha channel
+      // as blend factor, and doesn't allow us to set the alpha channel
+      c.color.red   = c.color.red   * alpha / 0xffff;
+      c.color.green = c.color.green * alpha / 0xffff;
+      c.color.blue  = c.color.blue  * alpha / 0xffff;
+
+      c.pixel = insert_component (c.color.red  , format->direct.redMask  , format->direct.red  )
+              | insert_component (c.color.green, format->direct.greenMask, format->direct.green)
+              | insert_component (c.color.blue , format->direct.blueMask , format->direct.blue )
+              | insert_component (alpha        , format->direct.alphaMask, format->direct.alpha);
+
+      return true;
+    }
+  else
+    {
+      XRenderColor d;
+
+      d.red   = color.r;
+      d.green = color.g;
+      d.blue  = color.b;
+      d.alpha = alpha;
+
+      // XftColorAlloc always returns 100% transparent pixels(!)
+      if (XftColorAllocValue (screen->dpy, screen->visual, screen->cmap, &d, &c))
+        return true;
+    }
+#else
+  c.red   = color.r;
+  c.green = color.g;
+  c.blue  = color.b;
+
+  if (screen->visual->c_class == TrueColor)
+    {
+      c.pixel = (color.r >> (16 - ecb_popcount32 (screen->visual->red_mask  )) << ecb_ctz32 (screen->visual->red_mask  ))
+              | (color.g >> (16 - ecb_popcount32 (screen->visual->green_mask)) << ecb_ctz32 (screen->visual->green_mask))
+              | (color.b >> (16 - ecb_popcount32 (screen->visual->blue_mask )) << ecb_ctz32 (screen->visual->blue_mask ));
+
+      return true;
+    }
+  else if (XAllocColor (screen->dpy, screen->cmap, &c))
+    return true;
+#endif
+
+  c.pixel = (color.r * 2 + color.g * 3 + color.b) >= 0x8000 * 6
+          ? WhitePixelOfScreen (DefaultScreenOfDisplay (screen->dpy))
+          : BlackPixelOfScreen (DefaultScreenOfDisplay (screen->dpy));
+
+  return false;
+}
+
+bool
+rxvt_color::set (rxvt_screen *screen, const char *name)
+{
+  rgba c;
+  char eos;
+  int skip = 0;
+
+  c.a = rgba::MAX_CC;
+
+  // parse the nonstandard "[alphapercent]" prefix
+  if (1 <= sscanf (name, "[%hd]%n", &c.a, &skip))
+    {
+      c.a = lerp<int, int, int> (0, rgba::MAX_CC, c.a);
+      name += skip;
+    }
+
+  // parse the non-standard "rgba:rrrr/gggg/bbbb/aaaa" format
+  if (strlen (name) != 4+5*4 || 4 != sscanf (name, "rgba:%4hx/%4hx/%4hx/%4hx%c", &c.r, &c.g, &c.b, &c.a, &eos))
+    {
+      XColor xc;
+
+      if (XParseColor (screen->dpy, screen->cmap, name, &xc))
+        {
+          c.r = xc.red;
+          c.g = xc.green;
+          c.b = xc.blue;
+        }
+      else
+        {
+          c.r = 0xffff;
+          c.g = 0x6969;
+          c.b = 0xb4b4;
+
+          rxvt_warn ("unable to parse color '%s', using pink instead.\n", name);
+        }
+    }
+
+  return set (screen, c);
+}
+
+bool
+rxvt_color::set (rxvt_screen *screen, const rgba &color)
+{
+  bool got = alloc (screen, color);
+
+#if !ENABLE_MINIMAL
+  int cmap_size = screen->visual->map_entries;
+
+  if (!got
+      && screen->visual->c_class == PseudoColor
+      && cmap_size < 4096)
+    {
+      XColor *colors = new XColor [screen->visual->map_entries];
+
+      for (int i = 0; i < cmap_size; i++)
+        colors [i].pixel = i;
+
+      // many kilobytes transfer per colour, but pseudocolor isn't worth
+      // many extra optimisations.
+      XQueryColors (screen->dpy, screen->cmap, colors, cmap_size);
+
+      while (cmap_size)
+        {
+          int diff = 0x7fffffffL;
+          XColor *best = colors;
+
+          for (int i = 0; i < cmap_size; i++)
+            {
+              // simple weighted rgb distance sucks, but keeps it simple
+              int d = abs (color.r - colors [i].red  ) * 2
+                    + abs (color.g - colors [i].green) * 3
+                    + abs (color.b - colors [i].blue );
+
+              if (d < diff)
+                {
+                  diff = d;
+                  best = colors + i;
+                }
+            }
+
+          //rxvt_warn ("could not allocate %04x %04x %04x, getting %04x %04x %04x instead (%d,%d)\n",
+          //    color.r, color.g, color.b, best->red, best->green, best->blue, diff, best - colors);
+
+          got = alloc (screen, rgba (best->red, best->green, best->blue));
+
+          if (got)
+            break;
+
+          *best = colors [--cmap_size];
+        }
+
+      delete [] colors;
+    }
+#endif
+
+  return got;
+}
+
+void
+rxvt_color::get (rgba &color) const
+{
+#if XFT
+
+  color.r = c.color.red;
+  color.g = c.color.green;
+  color.b = c.color.blue;
+  color.a = c.color.alpha;
+
+  if (IN_RANGE_INC (color.a, 0x0001, 0xfffe))
+    {
+      color.r = color.r * 0xffff / color.a;
+      color.g = color.g * 0xffff / color.a;
+      color.b = color.b * 0xffff / color.a;
+    }
+
+#else
+
+  color.r = c.red;
+  color.g = c.green;
+  color.b = c.blue;
+  color.a = rgba::MAX_CC;
+
+#endif
+}
+
+void
+rxvt_color::get (XColor &color) const
+{
+  rgba c;
+  get (c);
+
+  color.red   = c.r;
+  color.green = c.g;
+  color.blue  = c.b;
+  color.pixel = (Pixel)*this;
+}
+
+void
+rxvt_color::free (rxvt_screen *screen)
+{
+  if (screen->visual->c_class == TrueColor)
+    return; // nothing to do
+
+#if XFT
+  XftColorFree (screen->dpy, screen->visual, screen->cmap, &c);
+#else
+  XFreeColors (screen->dpy, screen->cmap, &c.pixel, 1, AllPlanes);
+#endif
+}
+
+void
+rxvt_color::fade (rxvt_screen *screen, int percent, rxvt_color &result, const rgba &to)
+{
+  rgba c;
+  get (c);
+
+  result.set (
+    screen,
+    rgba (
+      lerp (c.r, to.r, percent),
+      lerp (c.g, to.g, percent),
+      lerp (c.b, to.b, percent),
+      lerp (c.a, to.a, percent)
+    )
+  );
+}
+
+rxvt_selection::rxvt_selection (rxvt_display *disp, int selnum, Time tm, Window win, Atom prop, rxvt_term *term)
+: display (disp), request_time (tm), request_win (win), request_prop (prop), term (term)
+{
+  assert (selnum >= Sel_Primary && selnum <= Sel_Clipboard);
+
+  timer_ev.set<rxvt_selection, &rxvt_selection::timer_cb> (this);
+  timer_ev.repeat = 10.;
+  x_ev.set<rxvt_selection, &rxvt_selection::x_cb> (this);
+
+  incr_buf = 0;
+  incr_buf_size = incr_buf_fill = 0;
+  selection_wait = Sel_normal;
+  selection_type = selnum;
+  cb_sv = 0;
+}
+
+void
+rxvt_selection::stop ()
+{
+  free (incr_buf);
+  incr_buf = 0;
+  timer_ev.stop ();
+  x_ev.stop (display);
+}
+
+rxvt_selection::~rxvt_selection ()
+{
+  stop ();
+}
+
+void
+rxvt_selection::run ()
+{
+  int selnum = selection_type;
+
+#if ENABLE_FRILLS
+  if (selnum == Sel_Primary && display->selection_owner)
+    {
+      /* internal selection */
+      char *str = rxvt_wcstombs (display->selection_owner->selection.text, display->selection_owner->selection.len);
+      finish (str, strlen (str));
+      free (str);
+      return;
+    }
+#endif
+
+#if X_HAVE_UTF8_STRING
+  selection_type = Sel_UTF8String;
+  if (request (display->xa[XA_UTF8_STRING], selnum))
+    return;
+#else
+  selection_type = Sel_CompoundText;
+  if (request (display->xa[XA_COMPOUND_TEXT], selnum))
+    return;
+#endif
+
+  // fallback to CUT_BUFFER0 if the requested property has no owner
+  handle_selection (display->root, XA_CUT_BUFFER0, false);
+}
+
+void
+rxvt_selection::finish (char *data, unsigned int len)
+{
+  if (!cb_sv)
+    {
+      if (data)
+        term->paste (data, len);
+
+      term->selection_req = 0;
+      delete this;
+    }
+#if ENABLE_PERL
+  else
+    {
+      stop (); // we do not really trust perl callbacks
+      rxvt_perl.selection_finish (this, data, len);
+    }
+#endif
+}
+
+bool
+rxvt_selection::request (Atom target, int selnum)
+{
+  Atom sel;
+
+  selection_type |= selnum;
+
+  if (selnum == Sel_Primary)
+    sel = XA_PRIMARY;
+  else if (selnum == Sel_Secondary)
+    sel = XA_SECONDARY;
+  else
+    sel = display->xa[XA_CLIPBOARD];
+
+  if (XGetSelectionOwner (display->dpy, sel) != None)
+    {
+      XConvertSelection (display->dpy, sel, target, request_prop,
+                         request_win, request_time);
+      x_ev.start (display, request_win);
+      timer_ev.again ();
+      return true;
+    }
+
+  return false;
+}
+
+void
+rxvt_selection::handle_selection (Window win, Atom prop, bool delete_prop)
+{
+  Display *dpy = display->dpy;
+  char *data = 0;
+  unsigned int data_len = 0;
+  unsigned long bytes_after;
+  XTextProperty ct;
+
+  // check for failed XConvertSelection
+  if (prop == None)
+    {
+      bool error = true;
+      int selnum = selection_type & Sel_whereMask;
+
+      if (selection_type & Sel_CompoundText)
+        {
+          selection_type = 0;
+          error = !request (XA_STRING, selnum);
+        }
+
+      if (selection_type & Sel_UTF8String)
+        {
+          selection_type = Sel_CompoundText;
+          error = !request (display->xa[XA_COMPOUND_TEXT], selnum);
+        }
+
+      if (error)
+        {
+          ct.value = 0;
+          goto bailout;
+        }
+
+      return;
+    }
+
+  // length == (2^31 - 1) / 4, as gdk
+  if (XGetWindowProperty (dpy, win, prop,
+                          0, 0x1fffffff,
+                          delete_prop, AnyPropertyType,
+                          &ct.encoding, &ct.format,
+                          &ct.nitems, &bytes_after,
+                          &ct.value) != Success)
+    {
+      ct.value = 0;
+      goto bailout;
+    }
+
+  if (ct.encoding == None)
+    goto bailout;
+
+  if (ct.value == 0)
+    goto bailout;
+
+  if (ct.encoding == display->xa[XA_INCR])
+    {
+      // INCR selection, start handshake
+      if (!delete_prop)
+        XDeleteProperty (dpy, win, prop);
+
+      selection_wait = Sel_incr;
+      timer_ev.again ();
+
+      goto bailout;
+    }
+
+  if (ct.nitems == 0)
+    {
+      if (selection_wait == Sel_incr)
+        {
+          XFree (ct.value);
+
+          // finally complete, now paste the whole thing
+          selection_wait = Sel_normal;
+          ct.value = (unsigned char *)incr_buf;
+          ct.nitems = incr_buf_fill;
+          incr_buf = 0;
+          timer_ev.stop ();
+        }
+      else
+        {
+          // avoid recursion
+          if (win != display->root || prop != XA_CUT_BUFFER0)
+            {
+              XFree (ct.value);
+
+               // fallback to CUT_BUFFER0 if the requested property
+               // has an owner but is empty
+              handle_selection (display->root, XA_CUT_BUFFER0, False);
+              return;
+            }
+
+          goto bailout;
+        }
+    }
+  else if (selection_wait == Sel_incr)
+    {
+      timer_ev.again ();
+
+      while (incr_buf_fill + ct.nitems > incr_buf_size)
+        {
+          incr_buf_size = incr_buf_size ? incr_buf_size * 2 : 128*1024;
+          incr_buf = (char *)rxvt_realloc (incr_buf, incr_buf_size);
+        }
+
+      memcpy (incr_buf + incr_buf_fill, ct.value, ct.nitems);
+      incr_buf_fill += ct.nitems;
+
+      goto bailout;
+    }
+
+  char **cl;
+  int cr;
+
+  // we honour the first item only
+
+#if !ENABLE_MINIMAL
+  // xlib is horribly broken with respect to UTF8_STRING, and nobody cares to fix it
+  // so recode it manually
+  if (ct.encoding == display->xa[XA_UTF8_STRING])
+    {
+      wchar_t *w = rxvt_utf8towcs ((const char *)ct.value, ct.nitems);
+      data = rxvt_wcstombs (w);
+      free (w);
+    }
+  else
+#endif
+  if (XmbTextPropertyToTextList (dpy, &ct, &cl, &cr) >= 0
+      && cl)
+    {
+      data = strdup (cl[0]);
+      XFreeStringList (cl);
+    }
+  else
+    {
+      // paste raw
+      data = strdup ((const char *)ct.value);
+    }
+
+  data_len = strlen (data);
+
+bailout:
+  XFree (ct.value);
+
+  if (selection_wait == Sel_normal)
+    {
+      finish (data, data_len);
+      free (data);
+    }
+}
+
+void
+rxvt_selection::timer_cb (ev::timer &w, int revents)
+{
+  if (selection_wait == Sel_incr)
+    rxvt_warn ("data loss: timeout on INCR selection paste, ignoring.\n");
+
+  finish ();
+}