Commit: patch 9.0.2022: getmousepos() returns wrong index for TAB char

[Christian Brabandt]

patch 9.0.2022: getmousepos() returns wrong index for TAB char

Commit: https://github.com/vim/vim/commit/b583eda7031b1f6a3469a2537d0c10ca5fa5568e
Author: zeertzjq <zeer...@outlook.com>
Date: Sat Oct 14 11:32:28 2023 +0200

patch 9.0.2022: getmousepos() returns wrong index for TAB char

Problem: When clicking in the middle of a TAB, getmousepos() returns
the column of the next char instead of the TAB.
Solution: Break out of the loop when the vcol to find is inside current
char. Fix invalid memory access when calling virtcol2col() on
an empty line.

closes: #13321

Signed-off-by: Christian Brabandt <c...@256bit.org>
Co-authored-by: zeertzjq <zeer...@outlook.com>

diff --git a/runtime/doc/builtin.txt b/runtime/doc/builtin.txt
index 029c08bbd..f621fc051 100644
--- a/runtime/doc/builtin.txt
+++ b/runtime/doc/builtin.txt
@@ -10376,6 +10376,8 @@ virtcol2col({winid}, {lnum}, {col}) *virtcol2col()*
character in window {winid} at buffer line {lnum} and virtual
column {col}.

+ If buffer line {lnum} is an empty line, 0 is returned.
+
If {col} is greater than the last virtual column in line
{lnum}, then the byte index of the character at the last
virtual column is returned.
diff --git a/src/mouse.c b/src/mouse.c
index f3342f905..fe5c14cac 100644
--- a/src/mouse.c
+++ b/src/mouse.c
@@ -3201,7 +3201,7 @@ mouse_find_win(int *rowp, int *colp, mouse_find_T popup UNUSED)
|| defined(FEAT_EVAL) || defined(PROTO)
/*
* Convert a virtual (screen) column to a character column.
- * The first column is one.
+ * The first column is zero.
*/
int
vcol2col(win_T *wp, linenr_T lnum, int vcol)
@@ -3214,7 +3214,10 @@ vcol2col(win_T *wp, linenr_T lnum, int vcol)
init_chartabsize_arg(&cts, wp, lnum, 0, line, line);
while (cts.cts_vcol < vcol && *cts.cts_ptr != NUL)
{
- cts.cts_vcol += win_lbr_chartabsize(&cts, NULL);
+ int size = win_lbr_chartabsize(&cts, NULL);
+ if (cts.cts_vcol + size > vcol)
+ break;
+ cts.cts_vcol += size;
MB_PTR_ADV(cts.cts_ptr);
}
clear_chartabsize_arg(&cts);
diff --git a/src/move.c b/src/move.c
index 42878e4ad..72490d2f8 100644
--- a/src/move.c
+++ b/src/move.c
@@ -1547,14 +1547,17 @@ f_screenpos(typval_T *argvars UNUSED, typval_T *rettv)
static int
virtcol2col(win_T *wp, linenr_T lnum, int vcol)
{
- int offset = vcol2col(wp, lnum, vcol);
+ int offset = vcol2col(wp, lnum, vcol - 1);
char_u *line = ml_get_buf(wp->w_buffer, lnum, FALSE);
char_u *p = line + offset;

- // For a multibyte character, need to return the column number of the first
- // byte.
- MB_PTR_BACK(line, p);
-
+ if (*p == NUL)
+ {
+ if (p == line) // empty line
+ return 0;
+ // Move to the first byte of the last char.
+ MB_PTR_BACK(line, p);
+ }
return (int)(p - line + 1);
}

diff --git a/src/testdir/test_cursor_func.vim b/src/testdir/test_cursor_func.vim
index 4fc59288c..3cdf4cb7f 100644
--- a/src/testdir/test_cursor_func.vim
+++ b/src/testdir/test_cursor_func.vim
@@ -573,6 +573,11 @@ func Test_virtcol2col()
call assert_equal(8, virtcol2col(0, 1, 7))
call assert_equal(8, virtcol2col(0, 1, 8))

+ " These used to cause invalid memory access
+ call setline(1, '')
+ call assert_equal(0, virtcol2col(0, 1, 1))
+ call assert_equal(0, virtcol2col(0, 1, 2))
+
let w = winwidth(0)
call setline(2, repeat('a', w + 2))
let win_nosbr = win_getid()
diff --git a/src/testdir/test_functions.vim b/src/testdir/test_functions.vim
index bf0bf9036..50b7fb23c 100644
--- a/src/testdir/test_functions.vim
+++ b/src/testdir/test_functions.vim
@@ -3366,6 +3366,46 @@ func Test_getmousepos()
\ line: 1,
\ column: 1,
\ }, getmousepos())
+ call test_setmouse(1, 2)
+ call assert_equal(#{
+ \ screenrow: 1,
+ \ screencol: 2,
+ \ winid: win_getid(),
+ \ winrow: 1,
+ \ wincol: 2,
+ \ line: 1,
+ \ column: 1,
+ \ }, getmousepos())
+ call test_setmouse(1, 8)
+ call assert_equal(#{
+ \ screenrow: 1,
+ \ screencol: 8,
+ \ winid: win_getid(),
+ \ winrow: 1,
+ \ wincol: 8,
+ \ line: 1,
+ \ column: 1,
+ \ }, getmousepos())
+ call test_setmouse(1, 9)
+ call assert_equal(#{
+ \ screenrow: 1,
+ \ screencol: 9,
+ \ winid: win_getid(),
+ \ winrow: 1,
+ \ wincol: 9,
+ \ line: 1,
+ \ column: 2,
+ \ }, getmousepos())
+ call test_setmouse(1, 12)
+ call assert_equal(#{
+ \ screenrow: 1,
+ \ screencol: 12,
+ \ winid: win_getid(),
+ \ winrow: 1,
+ \ wincol: 12,
+ \ line: 1,
+ \ column: 2,
+ \ }, getmousepos())
call test_setmouse(1, 25)
call assert_equal(#{
\ screenrow: 1,
diff --git a/src/version.c b/src/version.c
index 2c9354634..d84210888 100644
--- a/src/version.c
+++ b/src/version.c
@@ -704,6 +704,8 @@ static char *(features[]) =

static int included_patches[] =
{ /* Add new patch number below this line */
+/**/
+ 2022,
/**/
2021,
/**/