patch 9.1.0116: win_split_ins may not check available room
Problem: win_split_ins has no check for E36 when moving an existing
window
Solution: check for room and fix the issues in f_win_splitmove()
(Sean Dewar)
win_split_ins has no check for E36 when moving an existing window,
allowing for layouts with many overlapping zero-sized windows to be
created (which may also cause drawing issues with tablines and such).
f_win_splitmove also has some bugs.
So check for room and fix the issues in f_win_splitmove. Handle failure
in the two relevant win_split_ins callers by restoring the original
layout, and factor the common logic into win_splitmove.
Don't check for room when opening an autocommand window, as it's a
temporary window that's rarely interacted with or drawn anyhow, and is
rather important for some autocommands.
Issues fixed in f_win_splitmove:
- Error if splitting is disallowed.
- Fix heap-use-after-frees if autocommands fired from switching to "targetwin"
close "wp" or "oldwin".
- Fix splitting the wrong window if autocommands fired from switching to
"targetwin" switch to a different window.
- Ensure -1 is returned for all errors.
Also handle allocation failure a bit earlier in make_snapshot (callers,
except win_splitmove, don't really care if a snapshot can't be made, so
just ignore the return value).
Note: Test_smoothscroll_in_zero_width_window failed after these changes with
E36, as it was using the previous behaviour to create a zero-width window.
I've fixed the test such that it fails with UBSAN as expected when v9.0.1367 is
reverted (and simplified it too).
related: #14042
Signed-off-by: Sean Dewar <6256228+seandewar@users.noreply.github.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/proto/window.pro b/src/proto/window.pro
index def28bb..97a25df 100644
--- a/src/proto/window.pro
+++ b/src/proto/window.pro
@@ -4,7 +4,9 @@
win_T *swbuf_goto_win_with_buf(buf_T *buf);
void do_window(int nchar, long Prenum, int xchar);
void get_wincmd_addr_type(char_u *arg, exarg_T *eap);
+int check_split_disallowed(win_T *wp);
int win_split(int size, int flags);
+int win_splitmove(win_T *wp, int size, int flags);
int win_split_ins(int size, int flags, win_T *new_wp, int dir);
int win_valid_popup(win_T *win);
int win_valid(win_T *win);
@@ -88,7 +90,7 @@
void check_lnums(int do_curwin);
void check_lnums_nested(int do_curwin);
void reset_lnums(void);
-void make_snapshot(int idx);
+int make_snapshot(int idx);
void restore_snapshot(int idx, int close_curwin);
int win_hasvertsplit(void);
int get_win_number(win_T *wp, win_T *first_win);