Don't generate git diff header for empty diffs

mercurial/patch.py

@@ -1,575 +1,576
 # patch.py - patch file parsing routines
 #
 # Copyright 2006 Brendan Cully <[e-mail]>
 #
 # This software may be used and distributed according to the terms
 # of the GNU General Public License, incorporated herein by reference.
 
 from demandload import demandload
 from i18n import gettext as _
 from node import *
 demandload(globals(), "cmdutil mdiff util")
 demandload(globals(), '''cStringIO email.Parser errno os re shutil sys tempfile
                          popen2''')
 
 # helper functions
 
 def copyfile(src, dst, basedir=None):
     if not basedir:
         basedir = os.getcwd()
 
     abssrc, absdst = [os.path.join(basedir, n) for n in (src, dst)]
     if os.path.exists(absdst):
         raise util.Abort(_("cannot create %s: destination already exists") %
                          dst)
 
     targetdir = os.path.dirname(absdst)
     if not os.path.isdir(targetdir):
         os.makedirs(targetdir)
     try:
         shutil.copyfile(abssrc, absdst)
         shutil.copymode(abssrc, absdst)
     except shutil.Error, inst:
         raise util.Abort(str(inst))
 
 # public functions
 
 def extract(ui, fileobj):
     '''extract patch from data read from fileobj.
 
     patch can be normal patch or contained in email message.
 
     return tuple (filename, message, user, date). any item in returned
     tuple can be None.  if filename is None, fileobj did not contain
     patch. caller must unlink filename when done.'''
 
     # attempt to detect the start of a patch
     # (this heuristic is borrowed from quilt)
     diffre = re.compile(r'^(?:Index:[ \t]|diff[ \t]|RCS file: |' +
                         'retrieving revision [0-9]+(\.[0-9]+)*$|' +
                         '(---|\*\*\*)[ \t])', re.MULTILINE)
 
     fd, tmpname = tempfile.mkstemp(prefix='hg-patch-')
     tmpfp = os.fdopen(fd, 'w')
     try:
         hgpatch = False
 
         msg = email.Parser.Parser().parse(fileobj)
 
         message = msg['Subject']
         user = msg['From']
         # should try to parse msg['Date']
         date = None
 
         if message:
             message = message.replace('\n\t', ' ')
             ui.debug('Subject: %s\n' % message)
         if user:
             ui.debug('From: %s\n' % user)
         diffs_seen = 0
         ok_types = ('text/plain', 'text/x-diff', 'text/x-patch')
 
         for part in msg.walk():
             content_type = part.get_content_type()
             ui.debug('Content-Type: %s\n' % content_type)
             if content_type not in ok_types:
                 continue
             payload = part.get_payload(decode=True)
             m = diffre.search(payload)
             if m:
                 ui.debug(_('found patch at byte %d\n') % m.start(0))
                 diffs_seen += 1
                 cfp = cStringIO.StringIO()
                 if message:
                     cfp.write(message)
                     cfp.write('\n')
                 for line in payload[:m.start(0)].splitlines():
                     if line.startswith('# HG changeset patch'):
                         ui.debug(_('patch generated by hg export\n'))
                         hgpatch = True
                         # drop earlier commit message content
                         cfp.seek(0)
                         cfp.truncate()
                     elif hgpatch:
                         if line.startswith('# User '):
                             user = line[7:]
                             ui.debug('From: %s\n' % user)
                         elif line.startswith("# Date "):
                             date = line[7:]
                     if not line.startswith('# '):
                         cfp.write(line)
                         cfp.write('\n')
                 message = cfp.getvalue()
                 if tmpfp:
                     tmpfp.write(payload)
                     if not payload.endswith('\n'):
                         tmpfp.write('\n')
             elif not diffs_seen and message and content_type == 'text/plain':
                 message += '\n' + payload
     except:
         tmpfp.close()
         os.unlink(tmpname)
         raise
 
     tmpfp.close()
     if not diffs_seen:
         os.unlink(tmpname)
         return None, message, user, date
     return tmpname, message, user, date
 
 def readgitpatch(patchname):
     """extract git-style metadata about patches from <patchname>"""
     class gitpatch:
         "op is one of ADD, DELETE, RENAME, MODIFY or COPY"
         def __init__(self, path):
             self.path = path
             self.oldpath = None
             self.mode = None
             self.op = 'MODIFY'
             self.copymod = False
             self.lineno = 0
 
     # Filter patch for git information
     gitre = re.compile('diff --git a/(.*) b/(.*)')
     pf = file(patchname)
     gp = None
     gitpatches = []
     # Can have a git patch with only metadata, causing patch to complain
     dopatch = False
 
     lineno = 0
     for line in pf:
         lineno += 1
         if line.startswith('diff --git'):
             m = gitre.match(line)
             if m:
                 if gp:
                     gitpatches.append(gp)
                 src, dst = m.group(1,2)
                 gp = gitpatch(dst)
                 gp.lineno = lineno
         elif gp:
             if line.startswith('--- '):
                 if gp.op in ('COPY', 'RENAME'):
                     gp.copymod = True
                     dopatch = 'filter'
                 gitpatches.append(gp)
                 gp = None
                 if not dopatch:
                     dopatch = True
                 continue
             if line.startswith('rename from '):
                 gp.op = 'RENAME'
                 gp.oldpath = line[12:].rstrip()
             elif line.startswith('rename to '):
                 gp.path = line[10:].rstrip()
             elif line.startswith('copy from '):
                 gp.op = 'COPY'
                 gp.oldpath = line[10:].rstrip()
             elif line.startswith('copy to '):
                 gp.path = line[8:].rstrip()
             elif line.startswith('deleted file'):
                 gp.op = 'DELETE'
             elif line.startswith('new file mode '):
                 gp.op = 'ADD'
                 gp.mode = int(line.rstrip()[-3:], 8)
             elif line.startswith('new mode '):
                 gp.mode = int(line.rstrip()[-3:], 8)
     if gp:
         gitpatches.append(gp)
 
     if not gitpatches:
         dopatch = True
 
     return (dopatch, gitpatches)
 
 def dogitpatch(patchname, gitpatches, cwd=None):
     """Preprocess git patch so that vanilla patch can handle it"""
     pf = file(patchname)
     pfline = 1
 
     fd, patchname = tempfile.mkstemp(prefix='hg-patch-')
     tmpfp = os.fdopen(fd, 'w')
 
     try:
         for i in range(len(gitpatches)):
             p = gitpatches[i]
             if not p.copymod:
                 continue
 
             copyfile(p.oldpath, p.path, basedir=cwd)
 
             # rewrite patch hunk
             while pfline < p.lineno:
                 tmpfp.write(pf.readline())
                 pfline += 1
             tmpfp.write('diff --git a/%s b/%s\n' % (p.path, p.path))
             line = pf.readline()
             pfline += 1
             while not line.startswith('--- a/'):
                 tmpfp.write(line)
                 line = pf.readline()
                 pfline += 1
             tmpfp.write('--- a/%s\n' % p.path)
 
         line = pf.readline()
         while line:
             tmpfp.write(line)
             line = pf.readline()
     except:
         tmpfp.close()
         os.unlink(patchname)
         raise
 
     tmpfp.close()
     return patchname
 
 def patch(patchname, ui, strip=1, cwd=None):
     """apply the patch <patchname> to the working directory.
     a list of patched files is returned"""
 
     # helper function
     def __patch(patchname):
         """patch and updates the files and fuzz variables"""
         files = {}
         fuzz = False
 
         patcher = util.find_in_path('gpatch', os.environ.get('PATH', ''),
                                     'patch')
         args = []
         if cwd:
             args.append('-d %s' % util.shellquote(cwd))
         fp = os.popen('%s %s -p%d < %s' % (patcher, ' '.join(args), strip,
                                            util.shellquote(patchname)))
 
         for line in fp:
             line = line.rstrip()
             ui.note(line + '\n')
             if line.startswith('patching file '):
                 pf = util.parse_patch_output(line)
                 printed_file = False
                 files.setdefault(pf, (None, None))
             elif line.find('with fuzz') >= 0:
                 fuzz = True
                 if not printed_file:
                     ui.warn(pf + '\n')
                     printed_file = True
                 ui.warn(line + '\n')
             elif line.find('saving rejects to file') >= 0:
                 ui.warn(line + '\n')
             elif line.find('FAILED') >= 0:
                 if not printed_file:
                     ui.warn(pf + '\n')
                     printed_file = True
                 ui.warn(line + '\n')
         code = fp.close()
         if code:
             raise util.Abort(_("patch command failed: %s") %
                              util.explain_exit(code)[0])
         return files, fuzz
 
     (dopatch, gitpatches) = readgitpatch(patchname)
 
     if dopatch:
         if dopatch == 'filter':
             patchname = dogitpatch(patchname, gitpatches, cwd=cwd)
         try:
             files, fuzz = __patch(patchname)
         finally:
             if dopatch == 'filter':
                 os.unlink(patchname)
     else:
         files, fuzz = {}, False
 
     for gp in gitpatches:
         files[gp.path] = (gp.op, gp)
 
     return (files, fuzz)
 
 def diffopts(ui, opts={}):
     return mdiff.diffopts(
         text=opts.get('text'),
         git=(opts.get('git') or
                   ui.configbool('diff', 'git', None)),
         nodates=(opts.get('nodates') or
                   ui.configbool('diff', 'nodates', None)),
         showfunc=(opts.get('show_function') or
                   ui.configbool('diff', 'showfunc', None)),
         ignorews=(opts.get('ignore_all_space') or
                   ui.configbool('diff', 'ignorews', None)),
         ignorewsamount=(opts.get('ignore_space_change') or
                         ui.configbool('diff', 'ignorewsamount', None)),
         ignoreblanklines=(opts.get('ignore_blank_lines') or
                           ui.configbool('diff', 'ignoreblanklines', None)))
 
 def updatedir(ui, repo, patches, wlock=None):
     '''Update dirstate after patch application according to metadata'''
     if not patches:
         return
     copies = []
     removes = []
     cfiles = patches.keys()
     cwd = repo.getcwd()
     if cwd:
         cfiles = [util.pathto(cwd, f) for f in patches.keys()]
     for f in patches:
         ctype, gp = patches[f]
         if ctype == 'RENAME':
             copies.append((gp.oldpath, gp.path, gp.copymod))
             removes.append(gp.oldpath)
         elif ctype == 'COPY':
             copies.append((gp.oldpath, gp.path, gp.copymod))
         elif ctype == 'DELETE':
             removes.append(gp.path)
     for src, dst, after in copies:
         if not after:
             copyfile(src, dst, repo.root)
         repo.copy(src, dst, wlock=wlock)
     if removes:
         repo.remove(removes, True, wlock=wlock)
     for f in patches:
         ctype, gp = patches[f]
         if gp and gp.mode:
             x = gp.mode & 0100 != 0
             dst = os.path.join(repo.root, gp.path)
             util.set_exec(dst, x)
     cmdutil.addremove(repo, cfiles, wlock=wlock)
     files = patches.keys()
     files.extend([r for r in removes if r not in files])
     files.sort()
 
     return files
 
 def diff(repo, node1=None, node2=None, files=None, match=util.always,
          fp=None, changes=None, opts=None):
     '''print diff of changes to files between two nodes, or node and
     working directory.
 
     if node1 is None, use first dirstate parent instead.
     if node2 is None, compare node1 with working directory.'''
 
     if opts is None:
         opts = mdiff.defaultopts
     if fp is None:
         fp = repo.ui
 
     if not node1:
         node1 = repo.dirstate.parents()[0]
 
     clcache = {}
     def getchangelog(n):
         if n not in clcache:
             clcache[n] = repo.changelog.read(n)
         return clcache[n]
     mcache = {}
     def getmanifest(n):
         if n not in mcache:
             mcache[n] = repo.manifest.read(n)
         return mcache[n]
     fcache = {}
     def getfile(f):
         if f not in fcache:
             fcache[f] = repo.file(f)
         return fcache[f]
 
     # reading the data for node1 early allows it to play nicely
     # with repo.status and the revlog cache.
     change = getchangelog(node1)
     mmap = getmanifest(change[0])
     date1 = util.datestr(change[2])
 
     if not changes:
         changes = repo.status(node1, node2, files, match=match)[:5]
     modified, added, removed, deleted, unknown = changes
     if files:
         def filterfiles(filters):
             l = [x for x in filters if x in files]
 
             for t in files:
                 if not t.endswith("/"):
                     t += "/"
                 l += [x for x in filters if x.startswith(t)]
             return l
 
         modified, added, removed = map(filterfiles, (modified, added, removed))
 
     if not modified and not added and not removed:
         return
 
     def renamedbetween(f, n1, n2):
         r1, r2 = map(repo.changelog.rev, (n1, n2))
         src = None
         while r2 > r1:
             cl = getchangelog(n2)[0]
             m = getmanifest(cl)
             try:
                 src = getfile(f).renamed(m[f])
             except KeyError:
                 return None
             if src:
                 f = src[0]
             n2 = repo.changelog.parents(n2)[0]
             r2 = repo.changelog.rev(n2)
         return src
 
     if node2:
         change = getchangelog(node2)
         mmap2 = getmanifest(change[0])
         _date2 = util.datestr(change[2])
         def date2(f):
             return _date2
         def read(f):
             return getfile(f).read(mmap2[f])
         def renamed(f):
             return renamedbetween(f, node1, node2)
     else:
         tz = util.makedate()[1]
         _date2 = util.datestr()
         def date2(f):
             try:
                 return util.datestr((os.lstat(repo.wjoin(f)).st_mtime, tz))
             except OSError, err:
                 if err.errno != errno.ENOENT: raise
                 return _date2
         def read(f):
             return repo.wread(f)
         def renamed(f):
             src = repo.dirstate.copied(f)
             parent = repo.dirstate.parents()[0]
             if src:
                 f = src[0]
             of = renamedbetween(f, node1, parent)
             if of:
                 return of
             elif src:
                 cl = getchangelog(parent)[0]
                 return (src, getmanifest(cl)[src])
             else:
                 return None
 
     if repo.ui.quiet:
         r = None
     else:
         hexfunc = repo.ui.verbose and hex or short
         r = [hexfunc(node) for node in [node1, node2] if node]
 
     if opts.git:
         copied = {}
         for f in added:
             src = renamed(f)
             if src:
                 copied[f] = src
         srcs = [x[1][0] for x in copied.items()]
 
     all = modified + added + removed
     all.sort()
     for f in all:
         to = None
         tn = None
         dodiff = True
+        header = []
         if f in mmap:
             to = getfile(f).read(mmap[f])
         if f not in removed:
             tn = read(f)
         if opts.git:
             def gitmode(x):
                 return x and '100755' or '100644'
             def addmodehdr(header, omode, nmode):
                 if omode != nmode:
                     header.append('old mode %s\n' % omode)
                     header.append('new mode %s\n' % nmode)
 
             a, b = f, f
-            header = []
             if f in added:
                 if node2:
                     mode = gitmode(mmap2.execf(f))
                 else:
                     mode = gitmode(util.is_exec(repo.wjoin(f), None))
                 if f in copied:
                     a, arev = copied[f]
                     omode = gitmode(mmap.execf(a))
                     addmodehdr(header, omode, mode)
                     op = a in removed and 'rename' or 'copy'
                     header.append('%s from %s\n' % (op, a))
                     header.append('%s to %s\n' % (op, f))
                     to = getfile(a).read(arev)
                 else:
                     header.append('new file mode %s\n' % mode)
             elif f in removed:
                 if f in srcs:
                     dodiff = False
                 else:
                     mode = gitmode(mmap.execf(f))
                     header.append('deleted file mode %s\n' % mode)
             else:
                 omode = gitmode(mmap.execf(f))
                 if node2:
                     nmode = gitmode(mmap2.execf(f))
                 else:
                     nmode = gitmode(util.is_exec(repo.wjoin(f), mmap.execf(f)))
                 addmodehdr(header, omode, nmode)
             r = None
+            header.insert(0, 'diff --git a/%s b/%s\n' % (a, b))
             if dodiff:
-                header.insert(0, 'diff --git a/%s b/%s\n' % (a, b))
+            text = mdiff.unidiff(to, date1, tn, date2(f), f, r, opts=opts)
+            if text or len(header) > 1:
                 fp.write(''.join(header))
-        if dodiff:
-            fp.write(mdiff.unidiff(to, date1, tn, date2(f), f, r, opts=opts))
+            fp.write(text)
 
 def export(repo, revs, template='hg-%h.patch', fp=None, switch_parent=False,
            opts=None):
     '''export changesets as hg patches.'''
 
     total = len(revs)
     revwidth = max(map(len, revs))
 
     def single(node, seqno, fp):
         parents = [p for p in repo.changelog.parents(node) if p != nullid]
         if switch_parent:
             parents.reverse()
         prev = (parents and parents[0]) or nullid
         change = repo.changelog.read(node)
 
         if not fp:
             fp = cmdutil.make_file(repo, template, node, total=total,
                                    seqno=seqno, revwidth=revwidth)
         if fp not in (sys.stdout, repo.ui):
             repo.ui.note("%s\n" % fp.name)
 
         fp.write("# HG changeset patch\n")
         fp.write("# User %s\n" % change[1])
         fp.write("# Date %d %d\n" % change[2])
         fp.write("# Node ID %s\n" % hex(node))
         fp.write("# Parent  %s\n" % hex(prev))
         if len(parents) > 1:
             fp.write("# Parent  %s\n" % hex(parents[1]))
         fp.write(change[4].rstrip())
         fp.write("\n\n")
 
         diff(repo, prev, node, fp=fp, opts=opts)
         if fp not in (sys.stdout, repo.ui):
             fp.close()
 
     for seqno, cset in enumerate(revs):
         single(cset, seqno, fp)
 
 def diffstat(patchlines):
     fd, name = tempfile.mkstemp(prefix="hg-patchbomb-", suffix=".txt")
     try:
         p = popen2.Popen3('diffstat -p1 -w79 2>/dev/null > ' + name)
         try:
             for line in patchlines: print >> p.tochild, line
             p.tochild.close()
             if p.wait(): return
             fp = os.fdopen(fd, 'r')
             stat = []
             for line in fp: stat.append(line.lstrip())
             last = stat.pop()
             stat.insert(0, last)
             stat = ''.join(stat)
             if stat.startswith('0 files'): raise ValueError
             return stat
         except: raise
     finally:
         try: os.unlink(name)
         except: pass