Merge pull request #12480 from nhooyr/mansect-trim

man.vim: Refactor verify_exists to unset $MANSECT as needed

2 files changed, 76 insertions, 28 deletions

diff --git a/runtime/autoload/man.vim b/runtime/autoload/man.vim
index 122ae357bc..930db3ceb7 100644
--- a/runtime/autoload/man.vim
+++ b/runtime/autoload/man.vim
@@ -52,13 +52,14 @@ function! man#open_page(count, count1, mods, ...) abort
     let ref = a:2.'('.a:1.')'
   endif
   try
-    let [sect, name] = man#extract_sect_and_name_ref(ref)
+    let [sect, name] = s:extract_sect_and_name_ref(ref)
     if a:count ==# a:count1
       " v:count defaults to 0 which is a valid section, and v:count1 defaults to
       " 1, also a valid section. If they are equal, count explicitly set.
       let sect = string(a:count)
     endif
-    let [sect, name, path] = s:verify_exists(sect, name)
+    let path = s:verify_exists(sect, name)
+    let [sect, name] = s:extract_sect_and_name_path(path)
   catch
     call s:error(v:exception)
     return
@@ -82,8 +83,9 @@ endfunction
 
 function! man#read_page(ref) abort
   try
-    let [sect, name] = man#extract_sect_and_name_ref(a:ref)
-    let [sect, name, path] = s:verify_exists(sect, name)
+    let [sect, name] = s:extract_sect_and_name_ref(a:ref)
+    let path = s:verify_exists(sect, name)
+    let [sect, name] = s:extract_sect_and_name_path(path)
     let page = s:get_page(path)
   catch
     call s:error(v:exception)
@@ -194,7 +196,7 @@ endfunction
 
 " attempt to extract the name and sect out of 'name(sect)'
 " otherwise just return the largest string of valid characters in ref
-function! man#extract_sect_and_name_ref(ref) abort
+function! s:extract_sect_and_name_ref(ref) abort
   if a:ref[0] ==# '-' " try ':Man -pandoc' with this disabled.
     throw 'manpage name cannot start with ''-'''
   endif
@@ -204,7 +206,7 @@ function! man#extract_sect_and_name_ref(ref) abort
     if empty(name)
       throw 'manpage reference cannot contain only parentheses'
     endif
-    return [get(b:, 'man_default_sects', ''), name]
+    return ['', name]
   endif
   let left = split(ref, '(')
   " see ':Man 3X curses' on why tolower.
@@ -227,24 +229,62 @@ function! s:get_path(sect, name) abort
   return substitute(get(split(s:system(['man', s:find_arg, s:section_arg, a:sect, a:name])), 0, ''), '\n\+$', '', '')
 endfunction
 
+" s:verify_exists attempts to find the path to a manpage
+" based on the passed section and name.
+"
+" 1. If the passed section is empty, b:man_default_sects is used.
+" 2. If manpage could not be found with the given sect and name,
+"    then another attempt is made with b:man_default_sects.
+" 3. If it still could not be found, then we try again without a section.
+" 4. If still not found but $MANSECT is set, then we try again with $MANSECT
+"    unset.
+"
+" This function is careful to avoid duplicating a search if a previous
+" step has already done it. i.e if we use b:man_default_sects in step 1,
+" then we don't do it again in step 2.
 function! s:verify_exists(sect, name) abort
+  let sect = a:sect
+  if empty(sect)
+    let sect = get(b:, 'man_default_sects', '')
+  endif
+
   try
-    let path = s:get_path(a:sect, a:name)
+    return s:get_path(sect, a:name)
   catch /^command error (/
+  endtry
+
+  if !empty(get(b:, 'man_default_sects', '')) && sect !=# b:man_default_sects
     try
-      let path = s:get_path(get(b:, 'man_default_sects', ''), a:name)
+      return s:get_path(b:man_default_sects, a:name)
     catch /^command error (/
-      let path = s:get_path('', a:name)
     endtry
-  endtry
-  " Extract the section from the path, because sometimes the actual section is
-  " more specific than what we provided to `man` (try `:Man 3 App::CLI`).
-  " Also on linux, name seems to be case-insensitive. So for `:Man PRIntf`, we
-  " still want the name of the buffer to be 'printf'.
-  return s:extract_sect_and_name_path(path) + [path]
+  endif
+
+  if !empty(sect)
+    try
+      return s:get_path('', a:name)
+    catch /^command error (/
+    endtry
+  endif
+
+  if !empty($MANSECT)
+    try
+      let MANSECT = $MANSECT
+      unset $MANSECT
+      return s:get_path('', a:name)
+    catch /^command error (/
+    finally
+      let $MANSECT = MANSECT
+    endtry
+  endif
+
+  throw 'no manual entry for ' . a:name
 endfunction
 
-" extracts the name and sect out of 'path/name.sect'
+" Extracts the name/section from the 'path/name.sect', because sometimes the actual section is
+" more specific than what we provided to `man` (try `:Man 3 App::CLI`).
+" Also on linux, name seems to be case-insensitive. So for `:Man PRIntf`, we
+" still want the name of the buffer to be 'printf'.
 function! s:extract_sect_and_name_path(path) abort
   let tail = fnamemodify(a:path, ':t')
   if a:path =~# '\.\%([glx]z\|bz2\|lzma\|Z\)$' " valid extensions
@@ -275,7 +315,7 @@ function! s:error(msg) abort
   echohl None
 endfunction
 
-" see man#extract_sect_and_name_ref on why tolower(sect)
+" see s:extract_sect_and_name_ref on why tolower(sect)
 function! man#complete(arg_lead, cmd_line, cursor_pos) abort
   let args = split(a:cmd_line)
   let cmd_offset = index(args, 'Man')
@@ -332,15 +372,26 @@ function! s:get_paths(sect, name, do_fallback) abort
   " callers must try-catch this, as some `man` implementations don't support `s:find_arg`
   try
     let mandirs = join(split(s:system(['man', s:find_arg]), ':\|\n'), ',')
-    return globpath(mandirs,'man?/'.a:name.'*.'.a:sect.'*', 0, 1)
+    let paths = globpath(mandirs, 'man?/'.a:name.'*.'.a:sect.'*', 0, 1)
+    try
+      " Prioritize the result from verify_exists as it obeys b:man_default_sects.
+      let first = s:verify_exists(a:sect, a:name)
+      let paths = filter(paths, 'v:val !=# first')
+      let paths = [first] + paths
+    catch
+    endtry
+    return paths
   catch
     if !a:do_fallback
       throw v:exception
     endif
 
-    " fallback to a single path, with the page we're trying to find
-    let [l:sect, l:name, l:path] = s:verify_exists(a:sect, a:name)
-    return [l:path]
+    " Fallback to a single path, with the page we're trying to find.
+    try
+      return [s:verify_exists(a:sect, a:name)]
+    catch
+      return []
+    endtry
   endtry
 endfunction
 
@@ -379,7 +430,7 @@ function! man#init_pager() abort
   " know the correct casing, cf. `man glDrawArraysInstanced`).
   let ref = substitute(matchstr(getline(1), '^[^)]\+)'), ' ', '_', 'g')
   try
-    let b:man_sect = man#extract_sect_and_name_ref(ref)[0]
+    let b:man_sect = s:extract_sect_and_name_ref(ref)[0]
   catch
     let b:man_sect = ''
   endtry
@@ -391,7 +442,7 @@ function! man#init_pager() abort
 endfunction
 
 function! man#goto_tag(pattern, flags, info) abort
-  let [l:sect, l:name] = man#extract_sect_and_name_ref(a:pattern)
+  let [l:sect, l:name] = s:extract_sect_and_name_ref(a:pattern)
 
   let l:paths = s:get_paths(l:sect, l:name, v:true)
   let l:structured = []
@@ -401,9 +452,6 @@ function! man#goto_tag(pattern, flags, info) abort
     let l:structured += [{ 'name': l:n, 'path': l:path }]
   endfor
 
-  " sort by relevance - exact matches first, then the previous order
-  call sort(l:structured, { a, b -> a.name ==? l:name ? -1 : b.name ==? l:name ? 1 : 0 })
-
   if &cscopetag
     " return only a single entry so we work well with :cstag (#11675)
     let l:structured = l:structured[:0]
diff --git a/runtime/ftplugin/man.vim b/runtime/ftplugin/man.vim
index 081181cfe9..0416e41368 100644
--- a/runtime/ftplugin/man.vim
+++ b/runtime/ftplugin/man.vim
@@ -6,7 +6,7 @@ if exists('b:did_ftplugin') || &filetype !=# 'man'
 endif
 let b:did_ftplugin = 1
 
-let s:pager = get(s:, 'pager', 0) || !exists('b:man_sect')
+let s:pager = !exists('b:man_sect')
 
 if s:pager
   call man#init_pager()
@@ -26,7 +26,7 @@ if !exists('g:no_plugin_maps') && !exists('g:no_man_maps')
   nnoremap <silent> <buffer> j          gj
   nnoremap <silent> <buffer> k          gk
   nnoremap <silent> <buffer> gO         :call man#show_toc()<CR>
-  if 1 == bufnr('%') || s:pager
+  if s:pager
     nnoremap <silent> <buffer> <nowait> q :lclose<CR>:q<CR>
   else
     nnoremap <silent> <buffer> <nowait> q :lclose<CR><C-W>c