Fix Copy/Paste problems on X11

The target of the TARGETS type should be XA_ATOM and not XA_TARGETS when
requested. Since we are sending a number of ATOMS the size should be set
to the integer size and not the char size.

The size field of the atoms is also the number of atoms and not the size
of the array. This caused some clients to wrongly interpret the data and
read garbage in the X11 packet.

I also add the more modern representation for UTF-8 and clarify the
error message if a client attempts to request a type we don't know
about.

This fixes #10431

(cherry picked from commit fb60f2dbe649c03a8357a277eccb6d06dfe07b68)

1 files changed, 29 insertions, 11 deletions

diff --git a/platform/x11/os_x11.cpp b/platform/x11/os_x11.cpp
index 7a2cbf26b..eaf72d4db 100644
--- a/platform/x11/os_x11.cpp
+++ b/platform/x11/os_x11.cpp
@@ -1862,8 +1862,12 @@ void OS_X11::process_xevents() {
 				e = event;
 
 				req = &(e.xselectionrequest);
-				if (req->target == XA_STRING || req->target == XInternAtom(x11_display, "COMPOUND_TEXT", 0) ||
-						req->target == XInternAtom(x11_display, "UTF8_STRING", 0)) {
+				if (req->target == XInternAtom(x11_display, "UTF8_STRING", 0) ||
+						req->target == XInternAtom(x11_display, "COMPOUND_TEXT", 0) ||
+						req->target == XInternAtom(x11_display, "TEXT", 0) ||
+						req->target == XA_STRING ||
+						req->target == XInternAtom(x11_display, "text/plain;charset=utf-8", 0) ||
+						req->target == XInternAtom(x11_display, "text/plain", 0)) {
 					CharString clip = OS::get_clipboard().utf8();
 					XChangeProperty(x11_display,
 							req->requestor,
@@ -1876,26 +1880,40 @@ void OS_X11::process_xevents() {
 					respond.xselection.property = req->property;
 				} else if (req->target == XInternAtom(x11_display, "TARGETS", 0)) {
 
-					Atom data[2];
-					data[0] = XInternAtom(x11_display, "UTF8_STRING", 0);
-					data[1] = XA_STRING;
-					XChangeProperty(x11_display, req->requestor, req->property, req->target,
-							8, PropModeReplace, (unsigned char *)&data,
-							sizeof(data));
+					Atom data[7];
+					data[0] = XInternAtom(x11_display, "TARGETS", 0);
+					data[1] = XInternAtom(x11_display, "UTF8_STRING", 0);
+					data[2] = XInternAtom(x11_display, "COMPOUND_TEXT", 0);
+					data[3] = XInternAtom(x11_display, "TEXT", 0);
+					data[4] = XA_STRING;
+					data[5] = XInternAtom(x11_display, "text/plain;charset=utf-8", 0);
+					data[6] = XInternAtom(x11_display, "text/plain", 0);
+
+					XChangeProperty(x11_display,
+							req->requestor,
+							req->property,
+							XA_ATOM,
+							32,
+							PropModeReplace,
+							(unsigned char *)&data,
+							sizeof(data) / sizeof(data[0]));
 					respond.xselection.property = req->property;
 
 				} else {
-					printf("No String %x\n",
-							(int)req->target);
+					char *targetname = XGetAtomName(x11_display, req->target);
+					printf("No Target '%s'\n", targetname);
+					if (targetname)
+						XFree(targetname);
 					respond.xselection.property = None;
 				}
+
 				respond.xselection.type = SelectionNotify;
 				respond.xselection.display = req->display;
 				respond.xselection.requestor = req->requestor;
 				respond.xselection.selection = req->selection;
 				respond.xselection.target = req->target;
 				respond.xselection.time = req->time;
-				XSendEvent(x11_display, req->requestor, 0, 0, &respond);
+				XSendEvent(x11_display, req->requestor, True, NoEventMask, &respond);
 				XFlush(x11_display);
 			} break;