x11: chunk selection paste property reads and guard against INCR transfers

1 files changed, 45 insertions, 12 deletions

diff --git a/src/x11/window.c b/src/x11/window.c
index 4b6f6fd..1a0db7d 100644
--- a/src/x11/window.c
+++ b/src/x11/window.c
@@ -90,7 +90,7 @@ struct x11_display {
     int depth;
     XIM im;
     Window selection_window;
-    Atom protocols, delete_window, utf8, clipboard, targets, paste_property;
+    Atom protocols, delete_window, utf8, clipboard, targets, paste_property, incr;
     Atom net_name, net_state, fullscreen, maximized_h, maximized_v;
     Atom xdnd_aware, xdnd_enter, xdnd_position, xdnd_status, xdnd_leave, xdnd_drop, xdnd_finished;
     Atom xdnd_selection, xdnd_action_copy, xdnd_type_list, uri_list;
@@ -1031,18 +1031,50 @@ static void selection_notify(struct x11_display *d, XSelectionEvent *event)
         free(r);
         return;
     }
-    Atom actual;
-    int format;
-    unsigned long count, left;
+    Atom actual = None;
+    int format = 0;
+    unsigned long count = 0, left = 0;
     unsigned char *data = NULL;
-    if (XGetWindowProperty(d->native, r->window, event->property,
-            0, TEXT_LIMIT / 4, True, AnyPropertyType,
-            &actual, &format, &count, &left, &data) == Success &&
-            (actual == d->utf8 || actual == XA_STRING) && format == 8 && !left) {
-        push(s, (struct yasl_input_event){.kind = YASL_INPUT_PASTE},
-                (const char *)data, count);
-    }
-    if (data) XFree(data);
+    char *buf = NULL;
+    size_t total = 0;
+    unsigned long offset = 0;
+
+    /* Read up to TEXT_LIMIT bytes in 64KB chunks to avoid huge single-request limits */
+    while (total < TEXT_LIMIT) {
+        unsigned long chunk = 16384; /* 64 KB (in 32-bit multiples) */
+        if (XGetWindowProperty(d->native, r->window, event->property,
+                (long)offset, (long)chunk, True, AnyPropertyType,
+                &actual, &format, &count, &left, &data) != Success || !actual) {
+            if (data) { XFree(data); data = NULL; }
+            break;
+        }
+        if (actual == d->incr) {
+            /* Unsupported INCR streaming transfer */
+            if (data) { XFree(data); data = NULL; }
+            break;
+        }
+        if ((actual != d->utf8 && actual != XA_STRING) || format != 8 || count == 0) {
+            if (data) { XFree(data); data = NULL; }
+            break;
+        }
+        char *nb = realloc(buf, total + count + 1);
+        if (!nb) {
+            XFree(data);
+            break;
+        }
+        buf = nb;
+        memcpy(buf + total, data, count);
+        total += count;
+        buf[total] = '\0';
+        offset += count / 4;
+        XFree(data);
+        data = NULL;
+        if (left == 0) break;
+    }
+    if (buf && total > 0) {
+        push(s, (struct yasl_input_event){.kind = YASL_INPUT_PASTE}, buf, total);
+        free(buf);
+    } else free(buf);
     XDestroyWindow(d->native, r->window);
     free(r);
 }
@@ -1531,6 +1563,7 @@ static struct yasl_display *display_open(struct yasl_loop *loop,
     ATOM(clipboard, "CLIPBOARD");
     ATOM(targets, "TARGETS");
     ATOM(paste_property, "YASL_SELECTION");
+    ATOM(incr, "INCR");
     ATOM(net_name, "_NET_WM_NAME");
     ATOM(net_state, "_NET_WM_STATE");
     ATOM(fullscreen, "_NET_WM_STATE_FULLSCREEN");