From 526365a8d13fc28ebb52042ccd2b8b29e0054ea7 Mon Sep 17 00:00:00 2001 From: phanium <91544758+phanen@users.noreply.github.com> Date: Wed, 22 Jul 2026 19:26:09 +0800 Subject: [PATCH] fix(help): handle escape edge cases #40901 * fix(help): preserve multi-letter CTRL modifiers in :help subject Problem: After PR 39537 normalized `CTRL-U-default` by excluding `-` from the trigger char class, the regex `(CTRL%-[^{])([^-_\\])` also fires between `CTRL-S` and the `H` of the `SHIFT` modifier in tags like `c_CTRL-SHIFT-V`, splitting it into the non-existent `c_CTRL-S_HIFT-V`. Solution: Exclude uppercase letters from the char class so a multi-letter modifier following `CTRL-X` (e.g. `SHIFT`, `ALT`) is no longer split. The `-` exclusion from 39537 is preserved so `i_CTRL-U-default` still works. * fix(help): escape ~ in expr-=~? exception to keep regex valid Problem: The `expr-=~?` exception in the tag alias table maps to `=~?`, but in Vim's regex engine `~` refers to the previous substitute pattern. With no prior substitute the pattern fails to compile, so `:help expr-=~?` returns E149 even though the tag exists. Solution: Escape `~` as \\\~` so the alias expands to a valid regex (`=\\\~?`) that substring-matches the `expr-=~?` tag. Other `expr-X?` entries are unaffected since they don't contain `~`. * fix(help): don't insert _ before CTRL- when preceded by - Problem: The rule `([^_])CTRL%- -> %1_CTRL-` inserts an underscore between any non-underscore char and `CTRL-`, which wrongly rewrites tags like `map-CTRL-C` and `telnet-CTRL-]` (where `CTRL-` is literal text in the tag, not a key chord). Solution: Exclude `-` from the trigger char class so a hyphen immediately before `CTRL-` is preserved. The existing behavior for `iCTRL-GCTRL-J` -> `i_CTRL-G_CTRL-J` is unaffected because the `G` before `CTRL-J` is not `-`. * fix(help): only treat ^X as caret notation for valid control chars Problem: The regex `%^([^_])` converts any `^X` to `CTRL-X`, including `:set^=` where `^=` is literal text in the tag, not a caret-notation control character. Solution: Restrict the transformation to caret-notation chars (`%a` or one of `?@[\\]^{}`). This matches the C reference behavior where `^X` is only converted when X is alphanumeric or one of the control-notation punctuation chars. `{` is retained so `^{char}` still maps to the `CTRL-{char}` placeholder tag. --- runtime/lua/vim/_core/help.lua | 12 ++++++++---- test/functional/ex_cmds/help_spec.lua | 7 +++++++ 2 files changed, 15 insertions(+), 4 deletions(-) diff --git a/runtime/lua/vim/_core/help.lua b/runtime/lua/vim/_core/help.lua index cc410daf17..0dad8f93ff 100644 --- a/runtime/lua/vim/_core/help.lua +++ b/runtime/lua/vim/_core/help.lua @@ -39,7 +39,7 @@ local tag_exceptions = { ['expr-<=?'] = '<=?', ['expr-=?'] = '>=?', ['expr->?'] = '>?', ['expr-is?'] = 'is?', @@ -103,12 +103,16 @@ function M.escape_subject(word) -- Change caret notation to 'CTRL-', except '^_' -- E.g. 'i^G^J' --> 'iCTRL-GCTRL-J' - word = word:gsub('%^([^_])', 'CTRL-%1') + -- Only treat '^' as control notation when followed by a caret-notation + -- char (a letter or one of "?@[\]^{"); otherwise leave it literal so + -- patterns like ':set^=' are not wrongly split. '{' is included so + -- '^{char}' matches the 'CTRL-{char}' placeholder tag. + word = word:gsub('%^([%a?@\\[\\%]{^])', 'CTRL-%1') -- Add underscores around 'CTRL-X' characters -- E.g. 'iCTRL-GCTRL-J' --> 'i_CTRL-G_CTRL-J' -- Only exception: 'CTRL-{character}' - word = word:gsub('([^_])CTRL%-', '%1_CTRL-') - word = word:gsub('(CTRL%-[^{])([^-_\\])', '%1_%2') + word = word:gsub('([^-_])CTRL%-', '%1_CTRL-') + word = word:gsub('(CTRL%-[^{])([^%u_\\-])', '%1_%2') -- Skip function arguments -- E.g. 'abs({expr})' --> 'abs' diff --git a/test/functional/ex_cmds/help_spec.lua b/test/functional/ex_cmds/help_spec.lua index 9263e23e3a..dcba0ac872 100644 --- a/test/functional/ex_cmds/help_spec.lua +++ b/test/functional/ex_cmds/help_spec.lua @@ -110,6 +110,7 @@ describe(':help', function() check_tag('help :[range]', '*:[range]*') check_tag('help [', '[') check_tag('help ]_^D', ']_CTRL-D') + check_tag('help :set^=', '*:set^=*') check_tag([[help $HOME]], [[*$HOME*]]) @@ -132,6 +133,12 @@ describe(':help', function() check_tag([[help i^x^y]], '*i_CTRL-X_CTRL-Y*') check_tag([[help CTRL-\_CTRL-N]], [[*CTRL-\_CTRL-N*]]) check_tag([[help i_CTRL-U-default]], [[*i_CTRL-U-default*]]) + check_tag([[help expr-=~?]], [[*expr-=~?*]]) + check_tag([[help map-CTRL-C]], '*map-CTRL-C*') + check_tag([=[help telnet-CTRL-]]=], '*telnet-CTRL-]*') + check_tag([[help c_CTRL-SHIFT-V]], '*c_CTRL-SHIFT-V*') + check_tag([[help i_CTRL-SHIFT-V]], '*i_CTRL-SHIFT-V*') + check_tag([[help c_CTRL-SHIFT-Q]], '*c_CTRL-SHIFT-Q*') check_tag([[exe "help i\\"]], [[*i_CTRL-\_CTRL-G*]]) check_tag([[exe "help \"]], '*CTRL-V*')