diff: add nobinary config to suppress git-style binary diffs

mercurial/mdiff.py

@@ -37,6 +37,7 b' class diffopts(object):'
         'showfunc': False,
         'git': False,
         'nodates': False,
+        'nobinary': False,
         'ignorews': False,
         'ignorewsamount': False,
         'ignoreblanklines': False,

mercurial/patch.py

@@ -1561,6 +1561,7 b' def diffopts(ui, opts=None, untrusted=Fa'
         text=opts and opts.get('text'),
         git=get('git'),
         nodates=get('nodates'),
+        nobinary=get('nobinary'),
         showfunc=get('show_function', 'showfunc'),
         ignorews=get('ignore_all_space', 'ignorews'),
         ignorewsamount=get('ignore_space_change', 'ignorewsamount'),
@@ -1815,7 +1816,7 b' def trydiff(repo, revs, ctx1, ctx2, modi'
         if dodiff:
             if opts.git or revs:
                 header.insert(0, diffline(join(a), join(b), revs))
-            if dodiff == 'binary':
+            if dodiff == 'binary' and not opts.nobinary:
                 text = mdiff.b85diff(to, tn)
                 if text:
                     addindexmeta(header, [gitindex(to), gitindex(tn)])

tests/test-diff-binary-file.t

@@ -37,4 +37,8 b''
 
   $ hg diff --git -r 0 -r 2
 
+  $ hg diff --config diff.nobinary=True --git -r 0 -r 1
+  diff --git a/binfile.bin b/binfile.bin
+  Binary file binfile.bin has changed
+
   $ cd ..