Minor tweaks to the fix for `insert-before-markers' overlay fix

(bug#58928)

* src/buffer.c (adjust_overlays_for_insert): wrap to less than 80
chars.
* src/itree.c: document BEFORE_MARKERS.

2 files changed, 6 insertions, 2 deletions

diff --git a/src/buffer.c b/src/buffer.c
index 745e62f53f7..390ccff5c8a 100644
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -3467,7 +3467,8 @@ adjust_overlays_for_insert (ptrdiff_t pos, ptrdiff_t length, bool before_markers
       itree_insert_gap (base->overlays, pos, length, before_markers);
       FOR_EACH_LIVE_BUFFER (tail, other)
         if (XBUFFER (other)->base_buffer == base)
-          itree_insert_gap (XBUFFER (other)->overlays, pos, length, before_markers);
+          itree_insert_gap (XBUFFER (other)->overlays, pos, length,
+                            before_markers);
     }
 }
 
diff --git a/src/itree.c b/src/itree.c
index c5e43bb0289..989f452cb92 100644
--- a/src/itree.c
+++ b/src/itree.c
@@ -1191,7 +1191,10 @@ itree_iterator_finish (struct itree_iterator *iter)
 
 /* Insert a gap at POS of length LENGTH expanding all intervals
    intersecting it, while respecting their rear_advance and
-   front_advance setting. */
+   front_advance setting.
+
+   When BEFORE_MARKERS, all overlays beginning/ending at POS are
+   treated as if their front_advance/rear_advance was true. */
 
 void
 itree_insert_gap (struct itree_tree *tree,