extdiff: do single file diffs from the wc with no copy

Extdiff was always making a temporary directory and copying files even when not required. This change makes extdiff avoid the copy when diffing a single file that lives in the wc. This lets external diff tools edit the working copy file directly. It also lets other extensions resuse the functions in extdiff and get in-place diffs.

hgext/extdiff.py

@@ -1,193 +1,215 b''
 # extdiff.py - external diff program support for mercurial
 #
 # Copyright 2006 Vadim Gelfer <[e-mail]>
 #
 # This software may be used and distributed according to the terms
 # of the GNU General Public License, incorporated herein by reference.
 #
 # The `extdiff' Mercurial extension allows you to use external programs
 # to compare revisions, or revision with working dir.  The external diff
 # programs are called with a configurable set of options and two
 # non-option arguments: paths to directories containing snapshots of
 # files to compare.
 #
 # To enable this extension:
 #
 #   [extensions]
 #   hgext.extdiff =
 #
 # The `extdiff' extension also allows to configure new diff commands, so
 # you do not need to type "hg extdiff -p kdiff3" always.
 #
 #   [extdiff]
 #   # add new command that runs GNU diff(1) in 'context diff' mode
 #   cmd.cdiff = gdiff
 #   opts.cdiff = -Nprc5
 
 #   # add new command called vdiff, runs kdiff3
 #   cmd.vdiff = kdiff3
 
 #   # add new command called meld, runs meld (no need to name twice)
 #   cmd.meld =
 
 #   # add new command called vimdiff, runs gvimdiff with DirDiff plugin
 #   #(see http://www.vim.org/scripts/script.php?script_id=102)
 #   # Non english user, be sure to put "let g:DirDiffDynamicDiffText = 1" in
 #   # your .vimrc
 #   cmd.vimdiff = gvim
 #   opts.vimdiff = -f '+next' '+execute "DirDiff" argv(0) argv(1)'
 #
 # Each custom diff commands can have two parts: a `cmd' and an `opts'
 # part.  The cmd.xxx option defines the name of an executable program
 # that will be run, and opts.xxx defines a set of command-line options
 # which will be inserted to the command between the program name and
 # the files/directories to diff (i.e. the cdiff example above).
 #
 # You can use -I/-X and list of file or directory names like normal
 # "hg diff" command.  The `extdiff' extension makes snapshots of only
 # needed files, so running the external diff program will actually be
 # pretty fast (at least faster than having to compare the entire tree).
 
 from mercurial.i18n import _
 from mercurial.node import *
 from mercurial import cmdutil, util
 import os, shutil, tempfile
 
 
 def snapshot_node(ui, repo, files, node, tmproot):
     '''snapshot files as of some revision'''
     mf = repo.changectx(node).manifest()
     dirname = os.path.basename(repo.root)
     if dirname == "":
         dirname = "root"
     dirname = '%s.%s' % (dirname, short(node))
     base = os.path.join(tmproot, dirname)
     os.mkdir(base)
     ui.note(_('making snapshot of %d files from rev %s\n') %
                  (len(files), short(node)))
     for fn in files:
         if not fn in mf:
             # skipping new file after a merge ?
             continue
         wfn = util.pconvert(fn)
         ui.note('  %s\n' % wfn)
         dest = os.path.join(base, wfn)
         destdir = os.path.dirname(dest)
         if not os.path.isdir(destdir):
             os.makedirs(destdir)
         data = repo.wwritedata(wfn, repo.file(wfn).read(mf[wfn]))
         open(dest, 'wb').write(data)
     return dirname
 
 
 def snapshot_wdir(ui, repo, files, tmproot):
     '''snapshot files from working directory.
     if not using snapshot, -I/-X does not work and recursive diff
     in tools like kdiff3 and meld displays too many files.'''
     dirname = os.path.basename(repo.root)
     if dirname == "":
         dirname = "root"
     base = os.path.join(tmproot, dirname)
     os.mkdir(base)
     ui.note(_('making snapshot of %d files from working dir\n') %
                  (len(files)))
     for fn in files:
         wfn = util.pconvert(fn)
         ui.note('  %s\n' % wfn)
         dest = os.path.join(base, wfn)
         destdir = os.path.dirname(dest)
         if not os.path.isdir(destdir):
             os.makedirs(destdir)
         fp = open(dest, 'wb')
         for chunk in util.filechunkiter(repo.wopener(wfn)):
             fp.write(chunk)
     return dirname
     
 
 def dodiff(ui, repo, diffcmd, diffopts, pats, opts):
     node1, node2 = cmdutil.revpair(repo, opts['rev'])
     files, matchfn, anypats = cmdutil.matchpats(repo, pats, opts)
     modified, added, removed, deleted, unknown = repo.status(
         node1, node2, files, match=matchfn)[:5]
     if not (modified or added or removed):
         return 0
 
     tmproot = tempfile.mkdtemp(prefix='extdiff.')
+    dir2root = ''
     try:
+        # Always make a copy of node1
         dir1 = snapshot_node(ui, repo, modified + removed, node1, tmproot)
+        changes = len(modified) + len(removed) + len(added)
+
+        # If node2 in not the wc or there is >1 change, copy it
         if node2:
             dir2 = snapshot_node(ui, repo, modified + added, node2, tmproot)
+        elif changes > 1:
+            dir2 = snapshot_wdir(ui, repo, modified + added, tmproot)
         else:
-            dir2 = snapshot_wdir(ui, repo, modified + added, tmproot)
+            # This lets the diff tool open the changed file directly
+            dir2 = ''
+            dir2root = repo.root
+
+        # If only one change, diff the files instead of the directories
+        if changes == 1 :
+            if len(modified):
+                dir1 = os.path.join(dir1, util.localpath(modified[0]))
+                dir2 = os.path.join(dir2root, dir2, util.localpath(modified[0]))  
+            elif len(removed) :
+                dir1 = os.path.join(dir1, util.localpath(removed[0]))
+                dir2 = os.devnull
+            else:
+                dir1 = os.devnull
+                dir2 = os.path.join(dir2root, dir2, util.localpath(added[0]))  
+    
         cmdline = ('%s %s %s %s' %
                    (util.shellquote(diffcmd), ' '.join(diffopts),
                     util.shellquote(dir1), util.shellquote(dir2)))
         ui.debug('running %r in %s\n' % (cmdline, tmproot))
         util.system(cmdline, cwd=tmproot)
         return 1
     finally:
         ui.note(_('cleaning up temp directory\n'))
         shutil.rmtree(tmproot)
 
 def extdiff(ui, repo, *pats, **opts):
     '''use external program to diff repository (or selected files)
 
     Show differences between revisions for the specified files, using
     an external program.  The default program used is diff, with
     default options "-Npru".
 
     To select a different program, use the -p option.  The program
     will be passed the names of two directories to compare.  To pass
     additional options to the program, use the -o option.  These will
     be passed before the names of the directories to compare.
 
     When two revision arguments are given, then changes are
     shown between those revisions. If only one revision is
     specified then that revision is compared to the working
     directory, and, when no revisions are specified, the
     working directory files are compared to its parent.'''
     program = opts['program'] or 'diff'
     if opts['program']:
         option = opts['option']
     else:
         option = opts['option'] or ['-Npru']
     return dodiff(ui, repo, program, option, pats, opts)
 
 cmdtable = {
     "extdiff":
     (extdiff,
      [('p', 'program', '', _('comparison program to run')),
       ('o', 'option', [], _('pass option to comparison program')),
       ('r', 'rev', [], _('revision')),
       ('I', 'include', [], _('include names matching the given patterns')),
       ('X', 'exclude', [], _('exclude names matching the given patterns'))],
      _('hg extdiff [OPT]... [FILE]...')),
     }
 
 def uisetup(ui):
     for cmd, path in ui.configitems('extdiff'):
         if not cmd.startswith('cmd.'): continue
         cmd = cmd[4:]
         if not path: path = cmd
         diffopts = ui.config('extdiff', 'opts.' + cmd, '')
         diffopts = diffopts and [diffopts] or []
         def save(cmd, path, diffopts):
             '''use closure to save diff command to use'''
             def mydiff(ui, repo, *pats, **opts):
                 return dodiff(ui, repo, path, diffopts, pats, opts)
             mydiff.__doc__ = '''use %(path)r to diff repository (or selected files)
 
             Show differences between revisions for the specified
             files, using the %(path)r program.
 
             When two revision arguments are given, then changes are
             shown between those revisions. If only one revision is
             specified then that revision is compared to the working
             directory, and, when no revisions are specified, the
             working directory files are compared to its parent.''' % {
                 'path': path,
                 }
             return mydiff
         cmdtable[cmd] = (save(cmd, path, diffopts),
                          cmdtable['extdiff'][1][1:],
                          _('hg %s [OPTION]... [FILE]...') % cmd)

tests/test-extdiff

@@ -1,34 +1,40 b''
 #!/bin/sh
 
 echo "[extensions]" >> $HGRCPATH
 echo "extdiff=" >> $HGRCPATH
 
 hg init a
 cd a
 echo a > a
+echo b > b
 hg add
+# should diff cloned directories
 hg extdiff -o -r $opt
 
 echo "[extdiff]" >> $HGRCPATH
 echo "cmd.falabala=echo" >> $HGRCPATH
 echo "opts.falabala=diffing" >> $HGRCPATH
 
 hg falabala
 
 hg help falabala
 
 hg ci -d '0 0' -mtest1
 
 echo b >> a
 hg ci -d '1 0' -mtest2
 
+# should diff cloned files directly 
 hg falabala -r 0:1
 
 # test diff during merge
 hg update 0
-echo b >> b
-hg add b
+echo c >> c
+hg add c
 hg ci -m "new branch" -d '1 0'
 hg update -C 1
 hg merge tip
-hg falabala || echo "diff-like tools yield a non-zero exit code"
+# should diff cloned file against wc file 
+hg falabala > out || echo "diff-like tools yield a non-zero exit code"
+# cleanup the output since the wc is a tmp directory
+sed  's:\(.* \).*\(\/test-extdiff\):\1[tmp]\2:' out

tests/test-extdiff.out

@@ -1,31 +1,33 b''
 adding a
+adding b
 Only in a: a
+Only in a: b
 diffing a.000000000000 a
 hg falabala [OPTION]... [FILE]...
 
 use 'echo' to diff repository (or selected files)
 
             Show differences between revisions for the specified
             files, using the 'echo' program.
 
             When two revision arguments are given, then changes are
             shown between those revisions. If only one revision is
             specified then that revision is compared to the working
             directory, and, when no revisions are specified, the
             working directory files are compared to its parent.
 
 options:
 
  -o --option   pass option to comparison program
  -r --rev      revision
  -I --include  include names matching the given patterns
  -X --exclude  exclude names matching the given patterns
 
 use "hg -v help falabala" to show global options
-diffing a.e27a2475d60a a.5e49ec8d3f05
+diffing a.8a5febb7f867/a a.34eed99112ab/a
 1 files updated, 0 files merged, 0 files removed, 0 files unresolved
 1 files updated, 0 files merged, 1 files removed, 0 files unresolved
 1 files updated, 0 files merged, 0 files removed, 0 files unresolved
 (branch merge, don't forget to commit)
-diffing a.5e49ec8d3f05 a
 diff-like tools yield a non-zero exit code
+diffing a.34eed99112ab/c [tmp]/test-extdiff/a/c