[PATCH] forget: add --dry-run mode

[Sushil khanchi]

# HG changeset patch
# User Sushil khanchi <sushilkhanchi97 at gmail.com>
# Date 1520665399 -19800
#      Sat Mar 10 12:33:19 2018 +0530
# Node ID 430c6b5123ee72d3a209882495302e43b26cc988
# Parent  4c71a26a4009d88590c9ae3d64a5912fd556d82e
forget: add --dry-run mode

diff -r 4c71a26a4009 -r 430c6b5123ee mercurial/cmdutil.py
--- a/mercurial/cmdutil.py	Sun Mar 04 21:16:36 2018 -0500
+++ b/mercurial/cmdutil.py	Sat Mar 10 12:33:19 2018 +0530
@@ -1996,7 +1996,7 @@
         for subpath in ctx.substate:
             ctx.sub(subpath).addwebdirpath(serverpath, webconf)
 
-def forget(ui, repo, match, prefix, explicitonly):
+def forget(ui, repo, match, prefix, explicitonly, **opts):
     join = lambda f: os.path.join(prefix, f)
     bad = []
     badfn = lambda x, y: bad.append(x) or match.bad(x, y)
@@ -2039,9 +2039,10 @@
         if ui.verbose or not match.exact(f):
             ui.status(_('removing %s\n') % match.rel(f))
 
-    rejected = wctx.forget(forget, prefix)
-    bad.extend(f for f in rejected if f in match.files())
-    forgot.extend(f for f in forget if f not in rejected)
+    if not opts.get('dry_run'):
+        rejected = wctx.forget(forget, prefix)
+        bad.extend(f for f in rejected if f in match.files())
+        forgot.extend(f for f in forget if f not in rejected)
     return bad, forgot
 
 def files(ui, ctx, m, fm, fmt, subrepos):
diff -r 4c71a26a4009 -r 430c6b5123ee mercurial/commands.py
--- a/mercurial/commands.py	Sun Mar 04 21:16:36 2018 -0500
+++ b/mercurial/commands.py	Sat Mar 10 12:33:19 2018 +0530
@@ -2036,7 +2036,10 @@
     with ui.formatter('files', opts) as fm:
         return cmdutil.files(ui, ctx, m, fm, fmt, opts.get('subrepos'))
 
- at command('^forget', walkopts, _('[OPTION]... FILE...'), inferrepo=True)
+ at command(
+    '^forget',
+    [('', 'dry-run', None, _('only print output'))]
+    + walkopts, _('[OPTION]... FILE...'), inferrepo=True)
 def forget(ui, repo, *pats, **opts):
     """forget the specified files on the next commit
 
@@ -2071,7 +2074,7 @@
         raise error.Abort(_('no files specified'))
 
     m = scmutil.match(repo[None], pats, opts)
-    rejected = cmdutil.forget(ui, repo, m, prefix="", explicitonly=False)[0]
+    rejected = cmdutil.forget(ui, repo, m, prefix="", explicitonly=False, **opts)[0]
     return rejected and 1 or 0
 
 @command(