From 6ddcc84a6cd725b386da5f6dea7f6512c1f501d3 Mon Sep 17 00:00:00 2001
From: zeertzjq <zeertzjq@outlook.com>
Date: Wed, 4 Mar 2026 07:42:05 +0800
Subject: [PATCH] vim-patch:9.2.0102: 'listchars' "leadtab" not used in :list
 (#38142)

Problem:  'listchars' "leadtab" not used in :list (after 9.2.0088).
Solution: Also check for "leadtab" when using :list. Fix memory leak on
          E1572 if "multispace" or "leadmultispace" is set (zeertzjq).

closes: vim/vim#19557

https://github.com/vim/vim/commit/5845741d69655a731288ab105c8fd9fe46e12df9
---
 src/nvim/message.c                  | 21 +++++++++++++++------
 src/nvim/optionstr.c                | 13 ++++++++++---
 test/old/testdir/gen_opt_test.vim   | 12 +++++++-----
 test/old/testdir/test_listchars.vim | 13 ++++++++++++-
 4 files changed, 44 insertions(+), 15 deletions(-)

diff --git a/src/nvim/message.c b/src/nvim/message.c
index 723362f681..f5ede4a8a1 100644
--- a/src/nvim/message.c
+++ b/src/nvim/message.c
@@ -2101,7 +2101,9 @@ void msg_prt_line(const char *s, bool list)
       }
     }
     // find end of leading whitespace
-    if (curwin->w_p_lcs_chars.lead || curwin->w_p_lcs_chars.leadmultispace != NULL) {
+    if (curwin->w_p_lcs_chars.lead
+        || curwin->w_p_lcs_chars.leadmultispace != NULL
+        || curwin->w_p_lcs_chars.leadtab1 != NUL) {
       lead = s;
       while (ascii_iswhite(lead[0])) {
         lead++;
@@ -2169,11 +2171,18 @@ void msg_prt_line(const char *s, bool list)
           sc = schar_from_ascii(' ');
           sc_extra = schar_from_ascii(' ');
         } else {
-          sc = (n_extra == 0 && curwin->w_p_lcs_chars.tab3)
-               ? curwin->w_p_lcs_chars.tab3
-               : curwin->w_p_lcs_chars.tab1;
-          sc_extra = curwin->w_p_lcs_chars.tab2;
-          sc_final = curwin->w_p_lcs_chars.tab3;
+          schar_T lcs_tab1 = curwin->w_p_lcs_chars.tab1;
+          schar_T lcs_tab2 = curwin->w_p_lcs_chars.tab2;
+          schar_T lcs_tab3 = curwin->w_p_lcs_chars.tab3;
+          // check if leadtab is set in 'listchars'
+          if (lead != NULL && s <= lead && curwin->w_p_lcs_chars.leadtab1 != NUL) {
+            lcs_tab1 = curwin->w_p_lcs_chars.leadtab1;
+            lcs_tab2 = curwin->w_p_lcs_chars.leadtab2;
+            lcs_tab3 = curwin->w_p_lcs_chars.leadtab3;
+          }
+          sc = (n_extra == 0 && lcs_tab3) ? lcs_tab3 : lcs_tab1;
+          sc_extra = lcs_tab2;
+          sc_final = lcs_tab3;
           hl_id = HLF_0;
         }
       } else if (c == NUL && list && curwin->w_p_lcs_chars.eol != NUL) {
diff --git a/src/nvim/optionstr.c b/src/nvim/optionstr.c
index 507294c6c6..91f52bbcd2 100644
--- a/src/nvim/optionstr.c
+++ b/src/nvim/optionstr.c
@@ -2313,6 +2313,8 @@ const char *set_chars_option(win_T *wp, const char *value, CharsOption what, boo
 
   // first round: check for valid value, second round: assign values
   for (int round = 0; round <= (apply ? 1 : 0); round++) {
+    bool has_tab = false, has_leadtab = false;
+
     if (round > 0) {
       // After checking that the value is valid: set defaults
       for (int i = 0; i < entries; i++) {
@@ -2456,6 +2458,11 @@ const char *set_chars_option(win_T *wp, const char *value, CharsOption what, boo
                                      tab[i].name.data);
             }
           }
+          if (tab[i].cp == &lcs_chars.tab2) {
+            has_tab = true;
+          } else {  // tab[i].cp == &lcs_chars.leadtab2
+            has_leadtab = true;
+          }
         }
 
         if (*s == ',' || *s == NUL) {
@@ -2489,10 +2496,10 @@ const char *set_chars_option(win_T *wp, const char *value, CharsOption what, boo
         p++;
       }
     }
-  }
 
-  if (what == kListchars && lcs_chars.leadtab2 != NUL && lcs_chars.tab2 == NUL) {
-    return e_leadtab_requires_tab;
+    if (what == kListchars && has_leadtab && !has_tab) {
+      return e_leadtab_requires_tab;
+    }
   }
 
   if (apply) {
diff --git a/test/old/testdir/gen_opt_test.vim b/test/old/testdir/gen_opt_test.vim
index 1c67cc6126..3b8c0ef6ff 100644
--- a/test/old/testdir/gen_opt_test.vim
+++ b/test/old/testdir/gen_opt_test.vim
@@ -276,11 +276,13 @@ let test_values = {
       "\ "		['xxx', ':none', 'xxx:', 'x:non', 'y:mok3', 'z:kittty']],
       \ 'langmap': [['', 'xX', 'aA,bB'], ['xxx']],
       \ 'lispoptions': [['', 'expr:0', 'expr:1'], ['xxx', 'expr:x', 'expr:']],
-      \ 'listchars': [['', 'eol:x', 'tab:xy', 'tab:xyz', 'space:x',
-      \		'multispace:xxxy', 'lead:x', 'tab:xy,leadtab:xyz', 'leadmultispace:xxxy',
-      \		'trail:x', 'extends:x', 'precedes:x', 'conceal:x', 'nbsp:x',
-      \		'eol:\\x24', 'eol:\\u21b5', 'eol:\\U000021b5', 'eol:x,space:y'],
-      \		['xxx', 'eol:', 'leadtab:xyz']],
+      \ 'listchars': [['', 'eol:x', 'tab:xy', 'tab:xyz', 'space:x', 'lead:x',
+      \		'multispace:xxxy', 'tab:xy,leadtab:xyz', 'leadtab:xyz,tab:xy',
+      \		'leadmultispace:xxxy', 'trail:x', 'extends:x', 'precedes:x',
+      \		'conceal:x', 'eol:\\x24', 'eol:\\u21b5', 'eol:\\U000021b5',
+      \		'eol:x,space:y', 'nbsp:x'],
+      \		['xxx', 'eol:', 'leadtab:xyz', 'multispace:xxxy,leadtab:xyz',
+      \		'leadmultispace:xxxy,leadtab:xyz,multispace:yyyx']],
       \ 'matchpairs': [['', '(:)', '(:),<:>'], ['xxx']],
       \ 'maxsearchcount': [[1, 10, 100, 1000], [0, -1, 10000]],
       \ 'messagesopt': [['hit-enter,history:1', 'hit-enter,history:10000',
diff --git a/test/old/testdir/test_listchars.vim b/test/old/testdir/test_listchars.vim
index 2191237576..3455984afd 100644
--- a/test/old/testdir/test_listchars.vim
+++ b/test/old/testdir/test_listchars.vim
@@ -392,6 +392,8 @@ func Test_listchars()
         \ 'text>---tab         '
         \ ]
   call Check_listchars(expected, 3, 20)
+  call assert_equal(expected->mapnew({_, s -> trim(s, ' ', 2)}) + [' '],
+                  \ split(execute("%list"), "\n"))
 
   " Test leadtab with unicode characters
   normal ggdG
@@ -399,6 +401,7 @@ func Test_listchars()
   call append(0, ["\ttext"])
   let expected = ['├──────┤text']
   call Check_listchars(expected, 1, 12)
+  call assert_equal(expected + [' '], split(execute("%list"), "\n"))
 
   " Test leadtab with mixed indentation (spaces + tabs)
   normal ggdG
@@ -406,6 +409,7 @@ func Test_listchars()
   call append(0, [" \t text"])
   let expected = ['.+******.text']
   call Check_listchars(expected, 1, 13)
+  call assert_equal(expected + [' '], split(execute("%list"), "\n"))
 
   " Test leadtab with pipe character
   normal ggdG
@@ -413,6 +417,7 @@ func Test_listchars()
   call append(0, ["\ttext"])
   let expected = ['|       text']
   call Check_listchars(expected, 1, 12)
+  call assert_equal(expected + [' '], split(execute("%list"), "\n"))
 
   " Test leadtab with unicode bar
   normal ggdG
@@ -420,6 +425,7 @@ func Test_listchars()
   call append(0, ["\ttext"])
   let expected = ['│       text']
   call Check_listchars(expected, 1, 12)
+  call assert_equal(expected + [' '], split(execute("%list"), "\n"))
 
   " Test leadtab vs tab distinction (leading vs non-leading)
   " In a line with only tabs, they aren't considered leading.
@@ -438,6 +444,8 @@ func Test_listchars()
         \ '>------->-------                '
         \ ]
   call Check_listchars(expected, 4, 32)
+  call assert_equal(expected->mapnew({_, s -> trim(s, ' ', 2)}) + [' '],
+                  \ split(execute("%list"), "\n"))
 
   " Test leadtab with trail and space
   normal ggdG
@@ -453,6 +461,8 @@ func Test_listchars()
         \ '+*******..text<<'
         \ ]
   call Check_listchars(expected, 3, 16)
+  call assert_equal(expected->mapnew({_, s -> trim(s, ' ', 2)}) + [' '],
+                  \ split(execute("%list"), "\n"))
 
   " Test leadtab with eol
   normal ggdG
@@ -463,7 +473,8 @@ func Test_listchars()
         \ 'text>---tab$ '
         \ ]
   call Check_listchars(expected, 2, 13)
-
+  call assert_equal(expected->mapnew({_, s -> trim(s, ' ', 2)}) + ['$'],
+                  \ split(execute("%list"), "\n"))
 
   " test nbsp
   normal ggdG