[PATCH 3 of 3] diffopts: notice a negated boolean flag in diffopts

[Augie Fackler]

# HG changeset patch
# User Augie Fackler <augie at google.com>
# Date 1471534521 14400
#      Thu Aug 18 11:35:21 2016 -0400
# Node ID 16491c79cf9b9b61550342690c680ed192506b08
# Parent  9ec3aad0bf74ad1c25e87bcd0f536896d1c355ca
diffopts: notice a negated boolean flag in diffopts

This means that if you have git-diffs enabled by default (pretty
common) and you hit the rare (but real) case where a git-diff breaks
patch(1) or some other tool, you can easily disable it by just
specifying --git=0 on the command line.

diff --git a/mercurial/patch.py b/mercurial/patch.py
--- a/mercurial/patch.py
+++ b/mercurial/patch.py
@@ -2142,7 +2142,7 @@ def difffeatureopts(ui, opts=None, untru
     def get(key, name=None, getter=ui.configbool, forceplain=None):
         if opts:
             v = opts.get(key)
-            if v:
+            if v or v is False:
                 return v
         if forceplain is not None and ui.plain():
             return forceplain
diff --git a/tests/test-diff-unified.t b/tests/test-diff-unified.t
--- a/tests/test-diff-unified.t
+++ b/tests/test-diff-unified.t
@@ -333,4 +333,20 @@ showfunc diff
   +    return a + b + c + e;
    }
 
+If [diff] git is set to true, but the user says --git=false, we should
+*not* get git diffs
+  $ hg diff --nodates --config diff.git=1 --git=false
+  diff -r f2c7c817fa55 f1
+  --- a/f1
+  +++ b/f1
+  @@ -2,6 +2,6 @@
+       int a = 0;
+       int b = 1;
+       int c = 2;
+  -    int d = 3;
+  -    return a + b + c + d;
+  +    int e = 3;
+  +    return a + b + c + e;
+   }
+
   $ cd ..