src/textprop.c (get_char_property_and_overlay): Fix bug#58479

Correct `get-char-property` which failed to ignore empty overlays.

* src/textprop.c (get_char_property_and_overlay): Make sure the
overlay covers the character.
* test/src/buffer-tests.el (buffer-tests--overlay-bug58479): New test.
* src/buffer.h (buffer_has_overlays): Avoid `interval_tree_size`.

2 files changed, 3 insertions, 2 deletions

diff --git a/src/buffer.h b/src/buffer.h
index 288acd4f5ee..deb0367d990 100644
--- a/src/buffer.h
+++ b/src/buffer.h
@@ -1275,7 +1275,7 @@ INLINE bool
 buffer_has_overlays (void)
 {
   return current_buffer->overlays
-    && (interval_tree_size (current_buffer->overlays) > 0);
+         && (current_buffer->overlays->root != ITREE_NULL);
 }
 
 /* Functions for accessing a character or byte,
diff --git a/src/textprop.c b/src/textprop.c
index 04fae528097..b34246f5bc7 100644
--- a/src/textprop.c
+++ b/src/textprop.c
@@ -649,7 +649,8 @@ get_char_property_and_overlay (Lisp_Object position, register Lisp_Object prop,
           Lisp_Object tem = Foverlay_get (node->data, prop);
           struct sortvec *this;
 
-          if (NILP (tem) || (w && ! overlay_matches_window (w, node->data)))
+          if (NILP (tem) || node->end < pos + 1
+              || (w && ! overlay_matches_window (w, node->data)))
             continue;
 
           this = (result == items ? items + 1 : items);