From cf5f6e97e8e037e0a5647735e262cc00ee1af022 Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Sun, 29 Dec 2024 17:22:06 +0530
Subject: [PATCH] Add some basic tests for multicell rewrap

---
 kitty/rewrap.c           | 56 +++++++++++++++++++++++-----------------
 kitty_tests/multicell.py | 34 ++++++++++++++++++++++++
 2 files changed, 66 insertions(+), 24 deletions(-)

diff --git a/kitty/rewrap.c b/kitty/rewrap.c
index a975b7ead..dc3d334a9 100644
--- a/kitty/rewrap.c
+++ b/kitty/rewrap.c
@@ -155,30 +155,6 @@ update_tracked_cursors(Rewrap *r, index_type num_cells, index_type y, index_type
     }
 }
 
-static void
-fast_copy_src_to_dest(Rewrap *r) {
-    CPUCell *c; index_type mc_width;
-    while (r->src_x < r->src_x_limit) {
-        if (r->dest_x >= r->dest_xnum) next_dest_line(r, true);
-        index_type num = MIN(r->src_x_limit - r->src_x, r->dest_xnum - r->dest_x);
-        bool do_copy = true;
-        if (num && (c = &r->src.cpu_cells[r->src_x + num - 1])->is_multicell && c->x != (mc_width = mcd_x_limit(c)) - 1) {
-            // we have a split multicell at the right edge of the copy region
-            if (num > mc_width) num -= mc_width;
-            else {
-                if (mc_width > r->dest_xnum) do_copy = false;
-                else {
-                    r->dest_x = r->dest_xnum;
-                    continue;
-                }
-            }
-        }
-        if (do_copy) copy_range(&r->src, r->src_x, &r->dest, r->dest_x, num);
-        update_tracked_cursors(r, num, r->src_y, r->src_x_limit);
-        r->src_x += num; r->dest_x += num;
-    }
-}
-
 static bool
 find_space_in_dest_line(Rewrap *r, index_type num_cells) {
     while (r->dest_x + num_cells <= r->dest_xnum) {
@@ -210,6 +186,7 @@ copy_multiline_extra_lines(Rewrap *r, CPUCell *src_cell, index_type mc_width) {
     }
 }
 
+
 static void
 multiline_copy_src_to_dest(Rewrap *r) {
     CPUCell *c; index_type mc_width;
@@ -231,6 +208,37 @@ multiline_copy_src_to_dest(Rewrap *r) {
     }
 }
 
+
+static void
+fast_copy_src_to_dest(Rewrap *r) {
+    CPUCell *c; index_type mc_width;
+    while (r->src_x < r->src_x_limit) {
+        if (r->dest_x >= r->dest_xnum) {
+            next_dest_line(r, true);
+            if (r->current_dest_line_has_multiline_cells) {
+                multiline_copy_src_to_dest(r);
+                return;
+            }
+        }
+        index_type num = MIN(r->src_x_limit - r->src_x, r->dest_xnum - r->dest_x);
+        bool do_copy = true;
+        if (num && (c = &r->src.cpu_cells[r->src_x + num - 1])->is_multicell && c->x != (mc_width = mcd_x_limit(c)) - 1) {
+            // we have a split multicell at the right edge of the copy region
+            if (num > mc_width) num = MIN(r->src_x_limit - r->src_x - mc_width, num);
+            else {
+                if (mc_width > r->dest_xnum) do_copy = false;
+                else {
+                    r->dest_x = r->dest_xnum;
+                    continue;
+                }
+            }
+        }
+        if (do_copy) copy_range(&r->src, r->src_x, &r->dest, r->dest_x, num);
+        update_tracked_cursors(r, num, r->src_y, r->src_x_limit);
+        r->src_x += num; r->dest_x += num;
+    }
+}
+
 static index_type
 rewrap_inner(Rewrap *r) {
     setup_line(r->text_cache, r->src_xnum, &r->src); setup_line(r->text_cache, r->dest_xnum, &r->dest);
diff --git a/kitty_tests/multicell.py b/kitty_tests/multicell.py
index 58200b22c..d7da303b7 100644
--- a/kitty_tests/multicell.py
+++ b/kitty_tests/multicell.py
@@ -459,3 +459,37 @@ def test_multicell(self: TestMulticell) -> None:
     multicell(s, 'a', scale=3)
     multicell(s, 'b', scale=2)
     ta('\x1b]66;w=1:s=3;a\x07\x1b]66;w=1:s=2;b\x07')
+
+    # rewrap with multicells
+    o = s.lines, s.columns
+    def reset():
+        s.resize(*o)
+        s.reset()
+
+    reset()
+    multicell(s, 'a', scale=2)
+    before = as_ansi()
+    s.resize(s.lines + 1, s.columns)
+    self.ae(before.rstrip(), as_ansi().rstrip())
+
+    reset()
+    s.draw('a' * (s.columns - 2) + '😛' + 'bb')
+    s.resize(s.lines, s.columns-1)
+    self.ae('\x1b[maaaa\x1b[m😛bb', as_ansi().rstrip())
+    reset()
+    s.draw('a' * (s.columns - 2) + '😛' + 'bb')
+    s.resize(s.lines, s.columns-2)
+    self.ae('\x1b[maaaa\x1b[m😛bb', as_ansi().rstrip())
+    reset()
+    s.draw('a' * (s.columns - 2) + '😛' + 'bb')
+    s.resize(s.lines, s.columns-3)
+    self.ae('\x1b[maaa\x1b[ma😛\x1b[mbb', as_ansi().rstrip()) # ]]]]]]]
+
+    reset()
+    multicell(s, 'a', scale=3)
+    s.draw('b'*(s.columns-3))
+    s.resize(s.lines, s.columns-1)
+    self.ae('\x1b[m\x1b]66;w=1:s=3;a\x07bb\x1b[mb', as_ansi().rstrip())  # ]]
+    ac(0, 0, is_multicell=True)
+    ac(0, 1, is_multicell=True)
+    ac(3, 1, is_multicell=False, text='b')