vim-patch:9.1.1818: possible crash when calculating topline in diff.c

Problem:  possible crash when calculating topline in diff.c
          (youngmith)
Solution: Check for pointer being Null before accessing it

fixes: vim/vim#18437

d32b3bb7eb

The POC is likely not applicable to Nvim due to #32160.

Co-authored-by: Christian Brabandt <cb@256bit.org>
This commit is contained in:
zeertzjq
2025-10-02 12:10:28 +08:00
parent dfd3ac6f48
commit df0b9e7a5d
2 changed files with 24 additions and 1 deletions

View File

@@ -2052,7 +2052,7 @@ static void calculate_topfill_and_topline(const int fromidx, const int toidx, co
// move the same amount of virtual lines in the target buffer to find the
// cursor's line number
int curlinenum_to = thistopdiff->df_lnum[toidx];
int curlinenum_to = thistopdiff != NULL ? thistopdiff->df_lnum[toidx] : 1;
int virt_lines_left = virtual_lines_passed;
curdif = thistopdiff;

View File

@@ -144,6 +144,28 @@ func Test_crash1_2()
call s:RunCommandAndWait(buf, args ..
\ ' ; echo "crash 5: [OK]" >> '.. result)
let file = 'Xdiff'
let lines =<< trim END
diffs a
edit Xdiff
file b
exe "norm! \<C-w>\<C-w>"
exe "norm! \<C-w>\<C-w>"
exe "norm! \<C-w>\<C-w>"
exe "norm! \<C-w>\<C-w>"
exe "norm! \<C-w>\<C-w>"
exe "norm! \<C-w>\L"
exe "norm! \<C-j>oy\<C-j>"
edit Xdiff
sil!so
END
call writefile(lines, file, 'D')
let cmn_args = "%s -u NONE -i NONE -X -m -n -e -s -u %s -c ':qa!'"
let args = printf(cmn_args, vim, file)
call s:RunCommandAndWait(buf, args ..
\ ' && echo "crash 6: [OK]" >> '.. result)
" clean up
exe buf .. "bw!"
exe "sp " .. result
@@ -153,6 +175,7 @@ func Test_crash1_2()
\ 'crash 3: [OK]',
\ 'crash 4: [OK]',
\ 'crash 5: [OK]',
\ 'crash 6: [OK]',
\ ]
call assert_equal(expected, getline(1, '$'))