Make also ShowHistory working with Mercurial.

Mercurial uses other temporary filenames than git. Match those,
if g:diffconflicts_vcs is set to 'hg'.

Author: Harald Klimach

plugin/diffconflicts.vim

@@ -70,17 +70,32 @@ function! s:showHistory()
     wincmd h
 
     " Populate each window.
-    buffer LOCAL
+    if g:diffconflicts_vcs == "hg"
+        buffer ~local.
+        file LOCAL
+    else
+        buffer LOCAL
+    endif
     setlocal nomodifiable readonly
     diffthis
 
     wincmd l
-    buffer BASE
+    if g:diffconflicts_vcs == "hg"
+        buffer ~base.
+        file BASE
+    else
+        buffer BASE
+    endif
     setlocal nomodifiable readonly
     diffthis
 
     wincmd l
-    buffer REMOTE
+    if g:diffconflicts_vcs == "hg"
+        buffer ~other.
+        file OTHER
+    else
+        buffer REMOTE
+    endif
     setlocal nomodifiable readonly
     diffthis
 
@@ -89,6 +104,11 @@ function! s:showHistory()
 endfunction
 
 function! s:checkThenShowHistory()
+    if g:diffconflicts_vcs == "hg"
+        let l:filecheck = 'v:val =~# "\\~base\\." || v:val =~# "\\~local\\." || v:val =~# "\\~other\\."'
+    else
+        let l:filecheck = 'v:val =~# "BASE" || v:val =~# "LOCAL" || v:val =~# "REMOTE"'
+    endif
     let l:xs =
         \ filter(
         \   map(
@@ -98,7 +118,7 @@ function! s:checkThenShowHistory()
         \     ),
         \     'bufname(v:val)'
         \   ),
-        \   'v:val =~# "BASE" || v:val =~# "LOCAL" || v:val =~# "REMOTE"'
+        \   l:filecheck
         \ )
 
     if (len(l:xs) < 3)