vim-patch:9.1.1188: runtime(tera): tera support can be improved (#32799)

Problem:  runtime(tera): tera support can be improved
Solution: update tera filetype plugin, include a tera syntax script
          update the filetype test, update makemenu and synmenu vim scripts
          (MuntasirSZN)

closes: vim/vim#16830

vim/vim@14da0fb

4 files changed, 138 insertions, 23 deletions

diff --git a/runtime/ftplugin/tera.vim b/runtime/ftplugin/tera.vim
index 47636f29fa..65bae70048 100644
--- a/runtime/ftplugin/tera.vim
+++ b/runtime/ftplugin/tera.vim
@@ -1,13 +1,30 @@
 " Vim filetype plugin file
 " Language:             Tera
 " Maintainer:           Muntasir Mahmud <muntasir.joypurhat@gmail.com>
-" Last Change:          2025 Mar 06
+" Last Change:          2025 Mar 08
 
 if exists("b:did_ftplugin")
   finish
 endif
 let b:did_ftplugin = 1
 
+setlocal autoindent
+
 setlocal commentstring={#\ %s\ #}
+setlocal comments=s:{#,e:#}
+
+if exists("loaded_matchit")
+  let b:match_ignorecase = 0
+  let b:match_words = '{#:##\|#},{% *if:{% *else\>:{% *elif\>:{% *endif %},{% *for\>:{% *endfor %},{% *macro\>:{% *endmacro %},{% *block\>:{% *endblock %},{% *filter\>:{% *endfilter %},{% *set\>:{% *endset %},{% *raw\>:{% *endraw %},{% *with\>:{% *endwith %}'
+endif
+
+setlocal includeexpr=substitute(v:fname,'\\([^.]*\\)$','\\1','g')
+setlocal suffixesadd=.tera
+
+setlocal expandtab
+setlocal shiftwidth=2
+setlocal softtabstop=2
 
-let b:undo_ftplugin = "setlocal commentstring<"
+let b:undo_ftplugin = "setlocal autoindent< commentstring< comments< " ..
+      \ "includeexpr< suffixesadd< expandtab< shiftwidth< softtabstop<"
+let b:undo_ftplugin .= "|unlet! b:match_ignorecase b:match_words"
diff --git a/runtime/makemenu.vim b/runtime/makemenu.vim
index 01f214cfa0..3d27bfc551 100644
--- a/runtime/makemenu.vim
+++ b/runtime/makemenu.vim
@@ -1,6 +1,6 @@
 " Script to define the syntax menu in synmenu.vim
 " Maintainer:	The Vim Project <https://github.com/vim/vim>
-" Last Change:	2023 Aug 10
+" Last Change:	2025 Mar 09
 " Former Maintainer:	Bram Moolenaar <Bram@vim.org>
 
 " This is used by "make menu" in the src directory.
@@ -602,6 +602,7 @@ SynMenu T.Tcl/Tk:tcl
 SynMenu T.TealInfo:tli
 SynMenu T.Telix\ Salt:tsalt
 SynMenu T.Termcap/Printcap:ptcap
+SynMenu T.Tera:tera
 SynMenu T.Terminfo:terminfo
 SynMenu T.Tera\ Term:teraterm
 SynMenu T.TeX.TeX/LaTeX:tex
diff --git a/runtime/synmenu.vim b/runtime/synmenu.vim
index edc6eabd1d..6a3bb8eaf4 100644
--- a/runtime/synmenu.vim
+++ b/runtime/synmenu.vim
@@ -582,26 +582,27 @@ an 50.150.190 &Syntax.T.TealInfo :cal SetSyn("tli")<CR>
 an 50.150.200 &Syntax.T.Telix\ Salt :cal SetSyn("tsalt")<CR>
 an 50.150.210 &Syntax.T.Termcap/Printcap :cal SetSyn("ptcap")<CR>
 an 50.150.220 &Syntax.T.Terminfo :cal SetSyn("terminfo")<CR>
-an 50.150.230 &Syntax.T.Tera\ Term :cal SetSyn("teraterm")<CR>
-an 50.150.240 &Syntax.T.TeX.TeX/LaTeX :cal SetSyn("tex")<CR>
-an 50.150.250 &Syntax.T.TeX.plain\ TeX :cal SetSyn("plaintex")<CR>
-an 50.150.260 &Syntax.T.TeX.Initex :cal SetSyn("initex")<CR>
-an 50.150.270 &Syntax.T.TeX.ConTeXt :cal SetSyn("context")<CR>
-an 50.150.280 &Syntax.T.TeX.TeX\ configuration :cal SetSyn("texmf")<CR>
-an 50.150.290 &Syntax.T.TeX.Texinfo :cal SetSyn("texinfo")<CR>
-an 50.150.300 &Syntax.T.TF\ mud\ client :cal SetSyn("tf")<CR>
-an 50.150.310 &Syntax.T.Tidy\ configuration :cal SetSyn("tidy")<CR>
-an 50.150.320 &Syntax.T.Tilde :cal SetSyn("tilde")<CR>
-an 50.150.330 &Syntax.T.Tmux\ configuration :cal SetSyn("tmux")<CR>
-an 50.150.340 &Syntax.T.TPP :cal SetSyn("tpp")<CR>
-an 50.150.350 &Syntax.T.Trasys\ input :cal SetSyn("trasys")<CR>
-an 50.150.360 &Syntax.T.Treetop :cal SetSyn("treetop")<CR>
-an 50.150.370 &Syntax.T.Trustees :cal SetSyn("trustees")<CR>
-an 50.150.380 &Syntax.T.TSS.Command\ Line :cal SetSyn("tsscl")<CR>
-an 50.150.390 &Syntax.T.TSS.Geometry :cal SetSyn("tssgm")<CR>
-an 50.150.400 &Syntax.T.TSS.Optics :cal SetSyn("tssop")<CR>
-an 50.150.410 &Syntax.T.Typescript :cal SetSyn("typescript")<CR>
-an 50.150.420 &Syntax.T.TypescriptReact :cal SetSyn("typescriptreact")<CR>
+an 50.150.230 &Syntax.T.Tera :cal SetSyn("tera")<CR>
+an 50.150.240 &Syntax.T.Tera\ Term :cal SetSyn("teraterm")<CR>
+an 50.150.250 &Syntax.T.TeX.TeX/LaTeX :cal SetSyn("tex")<CR>
+an 50.150.260 &Syntax.T.TeX.plain\ TeX :cal SetSyn("plaintex")<CR>
+an 50.150.270 &Syntax.T.TeX.Initex :cal SetSyn("initex")<CR>
+an 50.150.280 &Syntax.T.TeX.ConTeXt :cal SetSyn("context")<CR>
+an 50.150.290 &Syntax.T.TeX.TeX\ configuration :cal SetSyn("texmf")<CR>
+an 50.150.300 &Syntax.T.TeX.Texinfo :cal SetSyn("texinfo")<CR>
+an 50.150.310 &Syntax.T.TF\ mud\ client :cal SetSyn("tf")<CR>
+an 50.150.320 &Syntax.T.Tidy\ configuration :cal SetSyn("tidy")<CR>
+an 50.150.330 &Syntax.T.Tilde :cal SetSyn("tilde")<CR>
+an 50.150.340 &Syntax.T.Tmux\ configuration :cal SetSyn("tmux")<CR>
+an 50.150.350 &Syntax.T.TPP :cal SetSyn("tpp")<CR>
+an 50.150.360 &Syntax.T.Trasys\ input :cal SetSyn("trasys")<CR>
+an 50.150.370 &Syntax.T.Treetop :cal SetSyn("treetop")<CR>
+an 50.150.380 &Syntax.T.Trustees :cal SetSyn("trustees")<CR>
+an 50.150.390 &Syntax.T.TSS.Command\ Line :cal SetSyn("tsscl")<CR>
+an 50.150.400 &Syntax.T.TSS.Geometry :cal SetSyn("tssgm")<CR>
+an 50.150.410 &Syntax.T.TSS.Optics :cal SetSyn("tssop")<CR>
+an 50.150.420 &Syntax.T.Typescript :cal SetSyn("typescript")<CR>
+an 50.150.430 &Syntax.T.TypescriptReact :cal SetSyn("typescriptreact")<CR>
 an 50.160.100 &Syntax.UV.Udev\ config :cal SetSyn("udevconf")<CR>
 an 50.160.110 &Syntax.UV.Udev\ permissions :cal SetSyn("udevperm")<CR>
 an 50.160.120 &Syntax.UV.Udev\ rules :cal SetSyn("udevrules")<CR>
diff --git a/runtime/syntax/tera.vim b/runtime/syntax/tera.vim
new file mode 100644
index 0000000000..922b9c9752
--- /dev/null
+++ b/runtime/syntax/tera.vim
@@ -0,0 +1,96 @@
+" Vim syntax file
+" Language:	Tera
+" Maintainer:	Muntasir Mahmud <muntasir.joypurhat@gmail.com>
+" Last Change:	2025 Mar 09
+
+if exists("b:current_syntax")
+  finish
+endif
+
+" Detect the underlying language based on filename pattern
+" For files like file.html.tera, we want to load html syntax
+let s:filename = expand("%:t")
+let s:dotpos = strridx(s:filename, '.', strridx(s:filename, '.tera') - 1)
+let s:underlying_filetype = ""
+
+if s:dotpos != -1
+  let s:underlying_ext = s:filename[s:dotpos+1:strridx(s:filename, '.tera')-1]
+  if s:underlying_ext != "" && s:underlying_ext != "tera"
+    let s:underlying_filetype = s:underlying_ext
+  endif
+endif
+
+" Load the underlying language syntax if detected
+if s:underlying_filetype != ""
+  execute "runtime! syntax/" . s:underlying_filetype . ".vim"
+  unlet! b:current_syntax
+else
+  " Default to HTML if no specific language detected
+  runtime! syntax/html.vim
+  unlet! b:current_syntax
+endif
+
+" Tera comment blocks: {# comment #}
+syn region teraCommentBlock start="{#" end="#}" contains=@Spell containedin=cssDefinition,cssStyle,htmlHead,htmlTitle
+
+" Tera statements: {% if condition %}
+syn region teraStatement start="{%" end="%}" contains=teraKeyword,teraString,teraNumber,teraFunction,teraBoolean,teraFilter,teraOperator containedin=cssDefinition,cssStyle,htmlHead,htmlTitle
+
+" Tera expressions: {{ variable }}
+syn region teraExpression start="{{" end="}}" contains=teraString,teraNumber,teraFunction,teraBoolean,teraFilter,teraOperator,teraIdentifier containedin=cssDefinition,cssStyle,htmlHead,htmlTitle
+
+" Special handling for raw blocks - content inside shouldn't be processed
+syn region teraRawBlock start="{% raw %}" end="{% endraw %}" contains=TOP,teraCommentBlock,teraStatement,teraExpression
+
+" Control structure keywords
+syn keyword teraKeyword contained if else elif endif for endfor in macro endmacro
+syn keyword teraKeyword contained block endblock extends include import set endset
+syn keyword teraKeyword contained break continue filter endfilter raw endraw with endwith
+
+" Identifiers - define before operators for correct priority
+syn match teraIdentifier contained "\<\w\+\>"
+
+" Operators used in expressions and statements
+syn match teraOperator contained "==\|!=\|>=\|<=\|>\|<\|+\|-\|*\|/"
+syn match teraOperator contained "{\@<!%}\@!" " Match % but not when part of {% or %}
+syn keyword teraOperator contained and or not is as
+
+" Functions and filters
+syn match teraFunction contained "\<\w\+\ze("
+syn match teraFilter contained "|\_s*\w\+"
+
+" String literals - both single and double quoted
+syn region teraString contained start=+"+ skip=+\\"+ end=+"+ contains=@Spell
+syn region teraString contained start=+'+ skip=+\\'+ end=+'+ contains=@Spell
+
+" Numeric literals - both integer and float
+syn match teraNumber contained "\<\d\+\>"
+syn match teraNumber contained "\<\d\+\.\d\+\>"
+
+" Boolean values
+syn keyword teraBoolean contained true false
+
+" Highlighting links
+hi def link teraCommentBlock Comment
+hi def link teraKeyword Statement
+hi def link teraOperator Operator
+hi def link teraFunction Function
+hi def link teraIdentifier Identifier
+hi def link teraString String
+hi def link teraNumber Number
+hi def link teraBoolean Boolean
+hi def link teraFilter PreProc
+
+" Special highlighting for blocks and expressions
+hi def link teraStatement PreProc
+hi def link teraExpression PreProc
+
+" Clean up script-local variables
+unlet s:filename
+unlet s:dotpos
+if exists("s:underlying_ext")
+  unlet s:underlying_ext
+endif
+unlet s:underlying_filetype
+
+let b:current_syntax = "tera"