diff --git a/autoload/fugitive.vim b/autoload/fugitive.vim
index 6593380..d05a037 100644
--- a/autoload/fugitive.vim
+++ b/autoload/fugitive.vim
@@ -363,7 +363,7 @@ function! fugitive#Head(...) abort
   let head = readfile(fugitive#Find('.git/HEAD', dir))[0]
   if head =~# '^ref: '
     return substitute(head, '\C^ref: \%(refs/\%(heads/\|remotes/\|tags/\)\=\)\=', '', '')
-  elseif head =~# '^\x\{40\}$'
+  elseif head =~# '^\x\{40,\}$'
     let len = a:0 ? a:1 : 0
     return len < 0 ? head : len ? head[0:len-1] : ''
   else
@@ -373,7 +373,7 @@ endfunction
 
 function! fugitive#RevParse(rev, ...) abort
   let [hash, exec_error] = s:ChompError([a:0 ? a:1 : s:Dir(), 'rev-parse', '--verify', a:rev, '--'])
-  if !exec_error && hash =~# '^\x\{40\}$'
+  if !exec_error && hash =~# '^\x\{40,\}$'
     return hash
   endif
   call s:throw('rev-parse '.a:rev.': '.hash)
@@ -576,7 +576,7 @@ call s:add_methods('repo',['config', 'user'])
 " Section: File API
 
 function! s:DirCommitFile(path) abort
-  let vals = matchlist(s:Slash(a:path), '\c^fugitive:\%(//\)\=\(.\{-\}\)\%(//\|::\)\(\x\{40\}\|[0-3]\)\(/.*\)\=$')
+  let vals = matchlist(s:Slash(a:path), '\c^fugitive:\%(//\)\=\(.\{-\}\)\%(//\|::\)\(\x\{40,\}\|[0-3]\)\(/.*\)\=$')
   if empty(vals)
     return ['', '', '']
   endif
@@ -596,7 +596,7 @@ function! s:Owner(path, ...) abort
   let actualdir = fugitive#Find('.git/', dir)
   let [pdir, commit, file] = s:DirCommitFile(a:path)
   if s:cpath(dir, pdir)
-    if commit =~# '^\x\{40\}$'
+    if commit =~# '^\x\{40,\}$'
       return commit
     elseif commit ==# '2'
       return 'HEAD^{}'
@@ -789,7 +789,7 @@ function! fugitive#Find(object, ...) abort
           return file
         endif
       endif
-      if commit !~# '^[0-9a-f]\{40\}$'
+      if commit !~# '^[0-9a-f]\{40,\}$'
         let commit = s:ChompDefault('', [dir, 'rev-parse', '--verify', commit, '--'])
       endif
       if len(commit)
@@ -942,7 +942,7 @@ function! s:TreeInfo(dir, commit) abort
       endfor
     endif
     return [get(s:indexes[a:dir][1], a:commit[-1:-1], {}), newftime]
-  elseif a:commit =~# '^\x\{40\}$'
+  elseif a:commit =~# '^\x\{40,\}$'
     if !has_key(s:trees, a:dir)
       let s:trees[a:dir] = {}
     endif
@@ -1141,7 +1141,7 @@ function! fugitive#writefile(lines, url, ...) abort
     call call('writefile', [a:lines, temp] + a:000)
     let [hash, exec_error] = s:ChompError([dir, 'hash-object', '-w', temp])
     let mode = len(entry[1]) ? entry[1] : '100644'
-    if !exec_error && hash =~# '^\x\{40\}$'
+    if !exec_error && hash =~# '^\x\{40,\}$'
       let exec_error = s:SystemError([dir, 'update-index', '--index-info'],
             \ mode . ' ' . hash . ' ' . commit . "\t" . file[1:-1])[1]
       if !exec_error
@@ -2869,8 +2869,8 @@ function! s:RebaseEdit(cmd, dir) abort
     let shas = {}
 
     for i in range(len(new))
-      if new[i] =~# '^\l\+\s\+[0-9a-f]\{3,\}\>'
-        let sha = matchstr(new[i], '\C\v[a-f0-9]{5,40}')
+      if new[i] =~# '^\l\+\s\+[0-9a-f]\{5,\}\>'
+        let sha = matchstr(new[i], '\C\<[a-f0-9]\{5,\}\>')
         if !sha_length
           let sha_length = len(s:TreeChomp(a:dir, 'rev-parse', '--short', sha))
         endif
@@ -3027,10 +3027,10 @@ function! s:RebaseClean(file) abort
   for i in range(len(new))
     let new[i] = substitute(new[i], '^\l\>', '\=get(s:rebase_abbrevs,submatch(0),submatch(0))', '')
 
-    let sha = matchstr(new[i], '\C\v[a-f0-9]{5,40}')
+    let sha = matchstr(new[i], '\C\<[a-f0-9]\{5,\}\>')
     let rebase_shas = getbufvar(a:file, 'fugitive_rebase_shas')
     if len(sha) && type(rebase_shas) == type({}) && has_key(rebase_shas, sha)
-      let new[i] = substitute(new[i], sha, rebase_shas[sha], '')
+      let new[i] = substitute(new[i], '\C\<' . sha . '\>', rebase_shas[sha], '')
     endif
   endfor
   if new !=# old
@@ -3927,7 +3927,7 @@ endfunction
 
 function! s:BlameCommit(cmd, ...) abort
   let line = a:0 ? a:1 : getline('.')
-  if line =~# '^0\{4,40\} '
+  if line =~# '^0\{4,\} '
     return 'echoerr ' . string('Not Committed Yet')
   endif
   let cmd = s:Open(a:cmd, 0, '', matchstr(line, '\x\+'), [matchstr(line, '\x\+')])
@@ -4019,8 +4019,8 @@ function! s:BlameSyntax() abort
   let arg = exists('b:fugitive_blame_arguments') ? b:fugitive_blame_arguments : ''
   syn match FugitiveblameBoundary "^\^"
   syn match FugitiveblameBlank                      "^\s\+\s\@=" nextgroup=FugitiveblameAnnotation,fugitiveblameOriginalFile,FugitiveblameOriginalLineNumber skipwhite
-  syn match FugitiveblameHash       "\%(^\^\=\)\@<=\<\x\{7,40\}\>" nextgroup=FugitiveblameAnnotation,FugitiveblameOriginalLineNumber,fugitiveblameOriginalFile skipwhite
-  syn match FugitiveblameUncommitted "\%(^\^\=\)\@<=\<0\{7,40\}\>" nextgroup=FugitiveblameAnnotation,FugitiveblameOriginalLineNumber,fugitiveblameOriginalFile skipwhite
+  syn match FugitiveblameHash       "\%(^\^\=\)\@<=\<\x\{7,\}\>" nextgroup=FugitiveblameAnnotation,FugitiveblameOriginalLineNumber,fugitiveblameOriginalFile skipwhite
+  syn match FugitiveblameUncommitted "\%(^\^\=\)\@<=\<0\{7,\}\>" nextgroup=FugitiveblameAnnotation,FugitiveblameOriginalLineNumber,fugitiveblameOriginalFile skipwhite
   syn region FugitiveblameAnnotation matchgroup=FugitiveblameDelimiter start="(" end="\%( \d\+\)\@<=)" contained keepend oneline
   syn match FugitiveblameTime "[0-9:/+-][0-9:/+ -]*[0-9:/+-]\%( \+\d\+)\)\@=" contained containedin=FugitiveblameAnnotation
   exec 'syn match FugitiveblameLineNumber         " *\d\+)\@=" contained containedin=FugitiveblameAnnotation'.conceal
@@ -4135,7 +4135,7 @@ function! s:BrowseCommand(line1, line2, range, count, bang, mods, reg, arg, args
     endif
     if path =~# '^\.git/.*HEAD$' && filereadable(dir . '/' . path[5:-1])
       let body = readfile(dir . '/' . path[5:-1])[0]
-      if body =~# '^\x\{40\}$'
+      if body =~# '^\x\{40,\}$'
         let commit = body
         let type = 'commit'
         let path = ''
@@ -4192,7 +4192,7 @@ function! s:BrowseCommand(line1, line2, range, count, bang, mods, reg, arg, args
           if exec_error
             let commit = ''
           endif
-          if a:count && empty(a:args) && commit =~# '^\x\{40\}$'
+          if a:count && empty(a:args) && commit =~# '^\x\{40,\}$'
             let blame_list = tempname()
             call writefile([commit, ''], blame_list, 'b')
             let blame_in = tempname()
@@ -4354,7 +4354,7 @@ function! fugitive#MapJumps(...) abort
       nnoremap <buffer> <silent> O     :<C-U>exe <SID>GF("tabedit")<CR>
       nnoremap <buffer> <silent> p     :<C-U>exe <SID>GF("pedit")<CR>
     endif
-    exe "nnoremap <buffer> <silent>" nowait  "-     :<C-U>exe 'Gedit ' . <SID>fnameescape(<SID>NavigateUp(v:count1))<Bar> if getline(1) =~# '^tree \x\{40\}$' && empty(getline(2))<Bar>call search('^'.escape(expand('#:t'),'.*[]~\').'/\=$','wc')<Bar>endif<CR>"
+    exe "nnoremap <buffer> <silent>" nowait  "-     :<C-U>exe 'Gedit ' . <SID>fnameescape(<SID>NavigateUp(v:count1))<Bar> if getline(1) =~# '^tree \x\{40,\}$' && empty(getline(2))<Bar>call search('^'.escape(expand('#:t'),'.*[]~\').'/\=$','wc')<Bar>endif<CR>"
     nnoremap <buffer> <silent> P     :<C-U>exe 'Gedit ' . <SID>fnameescape(<SID>ContainingCommit().'^'.v:count1.<SID>Relative(':'))<CR>
     nnoremap <buffer> <silent> ~     :<C-U>exe 'Gedit ' . <SID>fnameescape(<SID>ContainingCommit().'~'.v:count1.<SID>Relative(':'))<CR>
     nnoremap <buffer> <silent> C     :<C-U>exe 'Gedit ' . <SID>fnameescape(<SID>ContainingCommit())<CR>
@@ -4466,7 +4466,7 @@ function! s:cfile() abort
     let treebase = substitute(s:DirCommitFile(@%)[1], '^\d$', ':&', '') . ':' .
           \ s:Relative('') . (s:Relative('') =~# '^$\|/$' ? '' : '/')
 
-    if getline('.') =~# '^\d\{6\} \l\{3,8\} \x\{40\}\t'
+    if getline('.') =~# '^\d\{6\} \l\{3,8\} \x\{40,\}\t'
       return [treebase . s:sub(matchstr(getline('.'),'\t\zs.*'),'/$','')]
     elseif showtree
       return [treebase . s:sub(getline('.'),'/$','')]
@@ -4476,8 +4476,8 @@ function! s:cfile() abort
       let dcmds = []
 
       " Index
-      if getline('.') =~# '^\d\{6\} \x\{40\} \d\t'
-        let ref = matchstr(getline('.'),'\x\{40\}')
+      if getline('.') =~# '^\d\{6\} \x\{40,\} \d\t'
+        let ref = matchstr(getline('.'),'\x\{40,\}')
         let file = ':'.s:sub(matchstr(getline('.'),'\d\t.*'),'\t',':')
         return [file]
       endif
@@ -4485,12 +4485,12 @@ function! s:cfile() abort
       if getline('.') =~# '^ref: '
         let ref = strpart(getline('.'),5)
 
-      elseif getline('.') =~# '^commit \x\{40\}\>'
-        let ref = matchstr(getline('.'),'\x\{40\}')
+      elseif getline('.') =~# '^commit \x\{40,\}\>'
+        let ref = matchstr(getline('.'),'\x\{40,\}')
         return [ref]
 
-      elseif getline('.') =~# '^parent \x\{40\}\>'
-        let ref = matchstr(getline('.'),'\x\{40\}')
+      elseif getline('.') =~# '^parent \x\{40,\}\>'
+        let ref = matchstr(getline('.'),'\x\{40,\}')
         let line = line('.')
         let parent = 0
         while getline(line) =~# '^parent '
@@ -4499,22 +4499,22 @@ function! s:cfile() abort
         endwhile
         return [ref]
 
-      elseif getline('.') =~# '^tree \x\{40\}$'
-        let ref = matchstr(getline('.'),'\x\{40\}')
+      elseif getline('.') =~# '^tree \x\{40,\}$'
+        let ref = matchstr(getline('.'),'\x\{40,\}')
         if len(myhash) && fugitive#RevParse(myhash.':') ==# ref
           let ref = myhash.':'
         endif
         return [ref]
 
-      elseif getline('.') =~# '^object \x\{40\}$' && getline(line('.')+1) =~ '^type \%(commit\|tree\|blob\)$'
-        let ref = matchstr(getline('.'),'\x\{40\}')
+      elseif getline('.') =~# '^object \x\{40,\}$' && getline(line('.')+1) =~ '^type \%(commit\|tree\|blob\)$'
+        let ref = matchstr(getline('.'),'\x\{40,\}')
         let type = matchstr(getline(line('.')+1),'type \zs.*')
 
       elseif getline('.') =~# '^\l\{3,8\} '.myhash.'$'
         let ref = s:DirRev(@%)[1]
 
-      elseif getline('.') =~# '^\l\{3,8\} \x\{40\}\>'
-        let ref = matchstr(getline('.'),'\x\{40\}')
+      elseif getline('.') =~# '^\l\{3,8\} \x\{40,\}\>'
+        let ref = matchstr(getline('.'),'\x\{40,\}')
         echoerr "warning: unknown context ".matchstr(getline('.'),'^\l*')
 
       elseif getline('.') =~# '^[+-]\{3\} [abciow12]\=/'
@@ -4558,10 +4558,10 @@ function! s:cfile() abort
         let ref = matchstr(line,'\Cdiff --git \%([abciow12]/.*\|/dev/null\) \zs\%([abciow12]/.*\|/dev/null\)')
         let dcmd = 'Gdiff!'
 
-      elseif line('$') == 1 && getline('.') =~ '^\x\{40\}$'
+      elseif line('$') == 1 && getline('.') =~ '^\x\{40,\}$'
         let ref = getline('.')
 
-      elseif expand('<cword>') =~# '^\x\{7,40\}\>'
+      elseif expand('<cword>') =~# '^\x\{7,\}\>'
         return [expand('<cword>')]
 
       else