Show refs in log in Gstatus

Display refs (the output of %d from git log's format=pretty) next
to commit summaries in Gstatus.

Use basic syntax highlighting for all refs.
Use a special marker and concealing to avoid false-positives when commit
subjects begin with parentheses.

Obvious refs (e.g. "HEAD", "origin/master" when showing unpulled changes
from "origin/master") are hidden.

autoload/fugitive.vim

@@ -1700,15 +1700,38 @@ function! s:ReplaceCmd(cmd) abort
   endif
 endfunction
 
-function! s:QueryLog(refspec) abort
-  let lines = s:LinesError(['log', '-n', '256', '--pretty=format:%h%x09%s', a:refspec, '--'])[0]
+function! s:IgnoreRefs(refs, refsToIgnore) abort
+  function! ShouldPreserveRef(refsToIgnore, index, ref) abort
+    return index(a:refsToIgnore, a:ref) == -1
+  endfunction
+
+  let refs = split(a:refs[1:-2], ", ")
+  let refs = filter(refs, function('ShouldPreserveRef', [a:refsToIgnore]))
+
+  if len(a:refs) == 0
+    return ''
+  endif
+
+  return '(' . join(refs, ", ") . ')'
+endfunction
+
+function! s:QueryLog(refspec, refToIgnore) abort
+  let lines = s:LinesError(['log', '-n', '256', '--pretty=format:%h%x09%d%x09%s', a:refspec, '--'])[0]
   call map(lines, 'split(v:val, "\t", 1)')
-  call map(lines, '{"type": "Log", "commit": v:val[0], "subject": join(v:val[1 : -1], "\t")}')
+  let refsToIgnore = [a:refToIgnore, 'HEAD']
+
+  function! HandleRefs(refsToIgnore, refs) abort
+    return s:IgnoreRefs(trim(a:refs), a:refsToIgnore)
+  endfunction
+
+  call map(lines, '{"type": "Log", "commit": v:val[0], "refs": ' . string(function('HandleRefs', [refsToIgnore])) . '(v:val[1]), "subject": join(v:val[2 : -1], "\t")}')
   return lines
 endfunction
 
 function! s:FormatLog(dict) abort
-  return a:dict.commit . ' ' . a:dict.subject
+  setlocal conceallevel=3
+  setlocal concealcursor=nc
+  return a:dict.commit . ' ' . ((len(a:dict.refs) > 0) ? ("\x1f" . a:dict.refs . ' ') : '') . a:dict.subject
 endfunction
 
 function! s:FormatRebase(dict) abort
@@ -1996,16 +2019,16 @@ function! fugitive#BufReadStatus() abort
     let staged_end = len(staged) ? line('$') : 0
 
     if len(pull) && get(props, 'branch.ab') !~# ' -0$'
-      call s:AddSection('Unpulled from ' . pull, s:QueryLog(head . '..' . pull))
+      call s:AddSection('Unpulled from ' . pull, s:QueryLog(head . '..' . pull, pull))
     endif
     if len(push) && push !=# pull
-      call s:AddSection('Unpulled from ' . push, s:QueryLog(head . '..' . push))
+      call s:AddSection('Unpulled from ' . push, s:QueryLog(head . '..' . push, push))
     endif
     if len(pull) && push !=# pull
-      call s:AddSection('Unpushed to ' . pull, s:QueryLog(pull . '..' . head))
+      call s:AddSection('Unpushed to ' . pull, s:QueryLog(pull . '..' . head, pull))
     endif
     if len(push) && !(push ==# pull && get(props, 'branch.ab') =~# '^+0 ')
-      call s:AddSection('Unpushed to ' . push, s:QueryLog(push . '..' . head))
+      call s:AddSection('Unpushed to ' . push, s:QueryLog(push . '..' . head, push))
     endif
 
     setlocal nomodified readonly noswapfile

syntax/fugitive.vim

@@ -23,8 +23,10 @@ syn match fugitiveDone /^done\>/ contained containedin=@fugitiveSection nextgrou
 syn match fugitiveStop /^stop\>/ contained containedin=@fugitiveSection nextgroup=fugitiveHash skipwhite
 syn match fugitiveModifier /^[MADRCU?]\{1,2} / contained containedin=@fugitiveSection
 syn match fugitiveSymbolicRef /\.\@!\%(\.\.\@!\|[^[:space:][:cntrl:]\:.]\)\+\.\@<!/ contained
-syn match fugitiveHash /^\x\{4,\}\S\@!/ contained containedin=@fugitiveSection
+syn match fugitiveHash /^\x\{4,\}\S\@!/ contained containedin=@fugitiveSection nextgroup=fugitiveRefsConcealedMarker skipwhite
 syn match fugitiveHash /\S\@<!\x\{4,\}\S\@!/ contained
+syn match fugitiveRefsConcealedMarker "\%x1f" contained nextgroup=fugitiveRefs conceal
+syn match fugitiveRefs /([^)]\+)/hs=s+1,he=e-1 contained
 
 syn region fugitiveHunk start=/^\%(@@\+ -\)\@=/ end=/^\%([A-Za-z?@]\|$\)\@=/ contains=@fugitiveDiff containedin=@fugitiveSection fold
 
@@ -51,6 +53,7 @@ hi def link fugitiveStagedModifier Typedef
 hi def link fugitiveInstruction Type
 hi def link fugitiveStop Function
 hi def link fugitiveHash Identifier
+hi def link fugitiveRefs Function
 hi def link fugitiveSymbolicRef Function
 hi def link fugitiveCount Number