From cf3662442feebfbe331b2dd9fc1fafde0f103a9d Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Fri, 9 Apr 2021 16:56:53 +0530
Subject: [PATCH] Fix #3460

---
 kitty/line-buf.c |  9 ---------
 kitty/lineops.h  |  1 -
 kitty/screen.c   | 12 ++++--------
 3 files changed, 4 insertions(+), 18 deletions(-)

diff --git a/kitty/line-buf.c b/kitty/line-buf.c
index beaf4ceda..f0d18156a 100644
--- a/kitty/line-buf.c
+++ b/kitty/line-buf.c
@@ -326,15 +326,6 @@ is_continued(LineBuf *self, PyObject *val) {
     Py_RETURN_FALSE;
 }
 
-unsigned int
-linebuf_continued_lines_count(const LineBuf *self, const index_type stop_before_line) {
-    index_type count = 0;
-    for (index_type i = 0; i < self->ynum && i < stop_before_line; i++) {
-      if (self->line_attrs[i] & CONTINUED_MASK) count++;
-    }
-    return count;
-}
-
 void
 linebuf_insert_lines(LineBuf *self, unsigned int num, unsigned int y, unsigned int bottom) {
     index_type i;
diff --git a/kitty/lineops.h b/kitty/lineops.h
index 77bde43eb..50443121e 100644
--- a/kitty/lineops.h
+++ b/kitty/lineops.h
@@ -91,7 +91,6 @@ void linebuf_clear(LineBuf *, char_type ch);
 void linebuf_index(LineBuf* self, index_type top, index_type bottom);
 void linebuf_reverse_index(LineBuf *self, index_type top, index_type bottom);
 void linebuf_clear_line(LineBuf *self, index_type y);
-unsigned int linebuf_continued_lines_count(const LineBuf *, const index_type);
 void linebuf_insert_lines(LineBuf *self, unsigned int num, unsigned int y, unsigned int bottom);
 void linebuf_delete_lines(LineBuf *self, index_type num, index_type y, index_type bottom);
 void linebuf_copy_line_to(LineBuf *, Line *, index_type);
diff --git a/kitty/screen.c b/kitty/screen.c
index 9431451a8..4a6118e1d 100644
--- a/kitty/screen.c
+++ b/kitty/screen.c
@@ -273,6 +273,7 @@ screen_resize(Screen *self, unsigned int lines, unsigned int columns) {
     index_type num_content_lines_before, num_content_lines_after, num_content_lines;
     unsigned int cursor_x = 0, cursor_y = 0;
     bool cursor_is_beyond_content = false;
+    unsigned int lines_after_cursor_before_resize = self->lines - self->cursor->y;
 #define setup_cursor() { \
         cursor_x = x; cursor_y = y; \
         cursor_is_beyond_content = num_content_lines_before > 0 && self->cursor->y >= num_content_lines_before; \
@@ -290,10 +291,6 @@ screen_resize(Screen *self, unsigned int lines, unsigned int columns) {
     if (n == NULL) return false;
 
 
-    int lines_to_fill = -1;
-    if (is_main && OPT(scrollback_fill_enlarged_window)) {
-        lines_to_fill = (lines - self->main_linebuf->ynum) + linebuf_continued_lines_count(self->main_linebuf, self->cursor->y + 1);
-    }
     Py_CLEAR(self->main_linebuf); self->main_linebuf = n;
     if (is_main) setup_cursor();
     grman_resize(self->main_grman, self->lines, lines, self->columns, columns);
@@ -329,14 +326,13 @@ screen_resize(Screen *self, unsigned int lines, unsigned int columns) {
         self->cursor->y = num_content_lines;
         if (self->cursor->y >= self->lines) { self->cursor->y = self->lines - 1; screen_index(self); }
     }
-    if (lines_to_fill > 0) {
-        lines_to_fill -= linebuf_continued_lines_count(self->main_linebuf, self->cursor->y + 1);
+    if (is_main && OPT(scrollback_fill_enlarged_window)) {
         const unsigned int top = 0, bottom = self->lines-1;
-        while (lines_to_fill-- > 0) {
+        while (self->cursor->y + 1 < self->lines && self->lines - self->cursor->y > lines_after_cursor_before_resize) {
             if (!historybuf_pop_line(self->historybuf, self->alt_linebuf->line)) break;
             INDEX_DOWN;
             linebuf_copy_line_to(self->main_linebuf, self->alt_linebuf->line, 0);
-            if (self->cursor->y + 1 < self->lines) self->cursor->y++;
+            self->cursor->y++;
         }
     }
     return true;