1 files changed, 68 insertions, 6 deletions

diff --git a/st.c b/st.c
index 274ac5d..17e0a65 100644
--- a/st.c
+++ b/st.c
@@ -452,6 +452,7 @@ static void focus(XEvent *);
 static void brelease(XEvent *);
 static void bpress(XEvent *);
 static void bmotion(XEvent *);
+static void propnotify(XEvent *);
 static void selnotify(XEvent *);
 static void selclear(XEvent *);
 static void selrequest(XEvent *);
@@ -500,6 +501,11 @@ static void (*handler[LASTEvent])(XEvent *) = {
  */
 /*      [SelectionClear] = selclear, */
         [SelectionNotify] = selnotify,
+/*
+ * PropertyNotify is only turned on when there is some INCR transfer happening
+ * for the selection retrieval.
+ */
+        [PropertyNotify] = propnotify,
         [SelectionRequest] = selrequest,
 };
 
@@ -1029,20 +1035,40 @@ selcopy(Time t)
 }
 
 void
+propnotify(XEvent *e)
+{
+        XPropertyEvent *xpev;
+        Atom clipboard = XInternAtom(xw.dpy, "CLIPBOARD", 0);
+
+        xpev = &e->xproperty;
+        if (xpev->state == PropertyNewValue &&
+                        (xpev->atom == XA_PRIMARY ||
+                         xpev->atom == clipboard)) {
+                slenotify(e);
+        }
+}
+
+void
 selnotify(XEvent *e)
 {
         ulong nitems, ofs, rem;
         int format;
         uchar *data, *last, *repl;
-        Atom type;
-        XSelectionEvent *xsev;
+        Atom type, incratom, property;
 
         ofs = 0;
-        xsev = &e->xselection;
-        if (xsev->property == None)
-            return;
+        if (e->type == SelectionNotify) {
+                property = e->xselection.property;
+        } else if(e->type == PropertyNotify) {
+                property = e->xproperty.atom;
+        } else {
+                return;
+        }
+        if (property == None)
+                return;
+
         do {
-                if (XGetWindowProperty(xw.dpy, xw.win, xsev->property, ofs,
+                if (XGetWindowProperty(xw.dpy, xw.win, property, ofs,
                                         BUFSIZ/4, False, AnyPropertyType,
                                         &type, &format, &nitems, &rem,
                                         &data)) {
@@ -1050,6 +1076,35 @@ selnotify(XEvent *e)
                         return;
                 }
 
+                if (e->type == PropertyNotify && nitems == 0 && rem == 0) {
+                        /*
+                         * If there is some PropertyNotify with no data, then
+                         * this is the signal of the selection owner that all
+                         * data has been transferred. We won't need to receive
+                         * PropertyNotify events anymore.
+                         */
+                        MODBIT(xw.attrs.event_mask, 0, PropertyChangeMask);
+                        XChangeWindowAttributes(xw.dpy, xw.win, CWEventMask,
+                                        &xw.attrs);
+                }
+
+                if (type == incratom) {
+                        /*
+                         * Activate the PropertyNotify events so we receive
+                         * when the selection owner does send us the next
+                         * chunk of data.
+                         */
+                        MODBIT(xw.attrs.event_mask, 1, PropertyChangeMask);
+                        XChangeWindowAttributes(xw.dpy, xw.win, CWEventMask,
+                                        &xw.attrs);
+
+                        /*
+                         * Deleting the property is the transfer start signal.
+                         */
+                        XDeleteProperty(xw.dpy, xw.win, (int)property);
+                        continue;
+                }
+
                 /*
                  * As seen in getsel:
                  * Line endings are inconsistent in the terminal and GUI world
@@ -1072,6 +1127,13 @@ selnotify(XEvent *e)
                 /* number of 32-bit chunks returned */
                 ofs += nitems * format / 32;
         } while (rem > 0);
+
+        /*
+         * Deleting the property again tells the selection owner to send the
+         * next data chunk in the property.
+         */
+        if (e->type == PropertyNotify)
+                XDeleteProperty(xw.dpy, xw.win, (int)property);
 }
 
 void