Add support for creating and removing files

Author: mingwandroid

patch.py

@@ -18,6 +18,7 @@
 import copy
 import logging
 import re
+import tempfile
 
 # cStringIO doesn't support unicode in 2.5
 try:
@@ -477,11 +478,26 @@ def lineno(self):
             # XXX header += srcname
             # double source filename line is encountered
             # attempt to restart from this second line
-          re_filename = b"^--- ([^\t]+)"
-          match = re.match(re_filename, line)
+
+            # Files dated at Unix epoch don't exist, e.g.:
+            # '1970-01-01 01:00:00.000000000 +0100'
+            # They include timezone offsets.
+            # .. which can be parsed (if we remove the nanoseconds)
+            # .. by strptime() with:
+            # '%Y-%m-%d %H:%M:%S %z'
+            # .. but unfortunately this relies on the OSes libc
+            # strptime function and %z support is patchy, so we drop
+            # everything from the . onwards and group the year and time
+            # separately.
+          re_filename_date_time = b"^--- ([^\t]+)(?:\s([0-9-]+)\s([0-9:]+)|.*)"
+          match = re.match(re_filename_date_time, line)
           # todo: support spaces in filenames
           if match:
             srcname = match.group(1).strip()
+            date = match.group(2)
+            time = match.group(3)
+            if (date == b'1970-01-01' or date == b'1969-12-31') and time.split(b':',1)[1] == b'00:00':
+              srcname = b'/dev/null'
           else:
             warning("skipping invalid filename at line %d" % (lineno+1))
             self.errors += 1
@@ -516,8 +532,8 @@ def lineno(self):
             filenames = False
             headscan = True
           else:
-            re_filename = b"^\+\+\+ ([^\t]+)"
-            match = re.match(re_filename, line)
+            re_filename_date_time = b"^\+\+\+ ([^\t]+)(?:\s([0-9-]+)\s([0-9:]+)|.*)"
+            match = re.match(re_filename_date_time, line)
             if not match:
               warning("skipping invalid patch - no target filename at line %d" % (lineno+1))
               self.errors += 1
@@ -526,12 +542,18 @@ def lineno(self):
               filenames = False
               headscan = True
             else:
+              tgtname = match.group(1).strip()
+              date = match.group(2)
+              time = match.group(3)
+              if (date == b'1970-01-01' or date == b'1969-12-31') and time.split(b':',1)[1] == b'00:00':
+                  tgtname = b'/dev/null'
               if p: # for the first run p is None
                 self.items.append(p)
               p = Patch()
               p.source = srcname
               srcname = None
-              p.target = match.group(1).strip()
+              p.target = tgtname
+              tgtname = None
               p.header = header
               header = []
               # switch to hunkhead state
@@ -729,16 +751,17 @@ def _normalize_filenames(self):
         while p.target.startswith(b".." + sep):
           p.target = p.target.partition(sep)[2]
       # absolute paths are not allowed
-      if xisabs(p.source) or xisabs(p.target):
+      if (xisabs(p.source) and p.source != b'/dev/null') or \
+         (xisabs(p.target) and p.target != b'/dev/null'):
         warning("error: absolute paths are not allowed - file no.%d" % (i+1))
         self.warnings += 1
-        if xisabs(p.source):
+        if xisabs(p.source) and p.source != b'/dev/null':
           warning("stripping absolute path from source name '%s'" % p.source)
           p.source = xstrip(p.source)
-        if xisabs(p.target):
+        if xisabs(p.target) and p.target != b'/dev/null':
           warning("stripping absolute path from target name '%s'" % p.target)
           p.target = xstrip(p.target)
-    
+
       self.items[i].source = p.source
       self.items[i].target = p.target
 
@@ -800,12 +823,23 @@ def diffstat(self):
     return output
 
 
-  def findfile(self, old, new):
-    """ return name of file to be patched or None """
-    if exists(old):
-      return old
+  def findfiles(self, old, new):
+    """ return tuple of source file, target file """
+    if old == b'/dev/null':
+      handle, abspath = tempfile.mkstemp(suffix=b'pypatch')
+      # The source file must contain a line for the hunk matching to succeed.
+      os.write(handle, b' ')
+      os.close(handle)
+      if not exists(new):
+        handle = open(new, 'wb')
+        handle.close()
+      return abspath, new
+    elif exists(old):
+      return old, old
     elif exists(new):
-      return new
+      return new, new
+    elif new == b'/dev/null':
+      return None, None
     else:
       # [w] Google Code generates broken patches with its online editor
       debug("broken patch from Google Code, stripping prefixes..")
@@ -814,10 +848,10 @@ def findfile(self, old, new):
         debug("   %s" % old)
         debug("   %s" % new)
         if exists(old):
-          return old
+          return old, old
         elif exists(new):
-          return new
-      return None
+          return new, new
+      return None, None
 
 
   def apply(self, strip=0, root=None):
@@ -848,27 +882,27 @@ def apply(self, strip=0, root=None):
         debug("stripping %s leading component(s) from:" % strip)
         debug("   %s" % p.source)
         debug("   %s" % p.target)
-        old = pathstrip(p.source, strip)
-        new = pathstrip(p.target, strip)
+        old = p.source if p.source == b'/dev/null' else pathstrip(p.source, strip)
+        new = p.target if p.target == b'/dev/null' else pathstrip(p.target, strip)
       else:
         old, new = p.source, p.target
 
-      filename = self.findfile(old, new)
+      filenameo, filenamen = self.findfiles(old, new)
 
-      if not filename:
+      if not filenameo or not filenamen:
           warning("source/target file does not exist:\n  --- %s\n  +++ %s" % (old, new))
           errors += 1
           continue
-      if not isfile(filename):
-        warning("not a file - %s" % filename)
+      if not isfile(filenameo):
+        warning("not a file - %s" % filenameo)
         errors += 1
         continue
 
       # [ ] check absolute paths security here
-      debug("processing %d/%d:\t %s" % (i+1, total, filename))
+      debug("processing %d/%d:\t %s" % (i+1, total, filenamen))
 
       # validate before patching
-      f2fp = open(filename, 'rb')
+      f2fp = open(filenameo, 'rb')
       hunkno = 0
       hunk = p.hunks[hunkno]
       hunkfind = []
@@ -891,7 +925,7 @@ def apply(self, strip=0, root=None):
           if line.rstrip(b"\r\n") == hunkfind[hunklineno]:
             hunklineno+=1
           else:
-            info("file %d/%d:\t %s" % (i+1, total, filename))
+            info("file %d/%d:\t %s" % (i+1, total, filenamen))
             info(" hunk no.%d doesn't match source file at line %d" % (hunkno+1, lineno+1))
             info("  expected: %s" % hunkfind[hunklineno])
             info("  actual  : %s" % line.rstrip(b"\r\n"))
@@ -911,8 +945,8 @@ def apply(self, strip=0, root=None):
               break
 
         # check if processed line is the last line
-        if lineno+1 == hunk.startsrc+len(hunkfind)-1:
-          debug(" hunk no.%d for file %s  -- is ready to be patched" % (hunkno+1, filename))
+        if len(hunkfind) == 0 or lineno+1 == hunk.startsrc+len(hunkfind)-1:
+          debug(" hunk no.%d for file %s  -- is ready to be patched" % (hunkno+1, filenamen))
           hunkno+=1
           validhunks+=1
           if hunkno < len(p.hunks):
@@ -924,34 +958,39 @@ def apply(self, strip=0, root=None):
               break
       else:
         if hunkno < len(p.hunks):
-          warning("premature end of source file %s at hunk %d" % (filename, hunkno+1))
+          warning("premature end of source file %s at hunk %d" % (filenameo, hunkno+1))
           errors += 1
 
       f2fp.close()
 
       if validhunks < len(p.hunks):
-        if self._match_file_hunks(filename, p.hunks):
-          warning("already patched  %s" % filename)
+        if self._match_file_hunks(filenameo, p.hunks):
+          warning("already patched  %s" % filenameo)
         else:
-          warning("source file is different - %s" % filename)
+          warning("source file is different - %s" % filenameo)
           errors += 1
       if canpatch:
-        backupname = filename+b".orig"
+        backupname = filenamen+b".orig"
         if exists(backupname):
           warning("can't backup original file to %s - aborting" % backupname)
         else:
           import shutil
-          shutil.move(filename, backupname)
-          if self.write_hunks(backupname, filename, p.hunks):
-            info("successfully patched %d/%d:\t %s" % (i+1, total, filename))
+          shutil.move(filenamen, backupname)
+          if self.write_hunks(backupname if filenameo == filenamen else filenameo, filenamen, p.hunks):
+            info("successfully patched %d/%d:\t %s" % (i+1, total, filenamen))
             os.unlink(backupname)
+            if new == b'/dev/null':
+              # check that filename is of size 0 and delete it.
+              if os.path.getsize(filenamen) > 0:
+                warning("expected patched file to be empty as it's marked as deletion:\t %s" % filenamen)
+              os.unlink(filenamen)
           else:
             errors += 1
-            warning("error patching file %s" % filename)
-            shutil.copy(filename, filename+".invalid")
-            warning("invalid version is saved to %s" % filename+".invalid")
+            warning("error patching file %s" % filenamen)
+            shutil.copy(filenamen, filenamen+".invalid")
+            warning("invalid version is saved to %s" % filenamen+".invalid")
             # todo: proper rejects
-            shutil.move(backupname, filename)
+            shutil.move(backupname, filenamen)
 
     if root:
       os.chdir(prevdir)

tests/08create/08create.patch

@@ -0,0 +1,5 @@
+diff -urN from/created to/created
+--- created	1970-01-01 01:00:00.000000000 +0100
++++ created	2016-06-07 00:43:08.701304500 +0100
+@@ -0,0 +1 @@
++Created by patch

tests/08create/[result]/created

@@ -0,0 +1 @@
+Created by patch

tests/09delete/09delete.patch

@@ -0,0 +1,5 @@
+diff -urN from/deleted to/deleted
+--- deleted	2016-06-07 00:44:19.093323300 +0100
++++ deleted	1970-01-01 01:00:00.000000000 +0100
+@@ -1 +0,0 @@
+-Deleted by patch

tests/09delete/[result]/.gitkeep

@@ -0,0 +1 @@
+

tests/09delete/deleted

@@ -0,0 +1 @@
+Deleted by patch

tests/run_tests.py

@@ -169,7 +169,7 @@ def _run_test(self, testname):
         # recursive comparison
         self._assert_dirs_equal(join(basepath, "[result]"),
                                 tmpdir,
-                                ignore=["%s.patch" % testname, ".svn", "[result]"])
+                                ignore=["%s.patch" % testname, ".svn", ".gitkeep", "[result]"])
 
 
       shutil.rmtree(tmpdir)
@@ -410,6 +410,20 @@ def test_apply_strip(self):
           p.target = b'nasty/prefix/' + p.target
         self.assertTrue(pto.apply(strip=2, root=treeroot))
 
+    def test_create_file(self):
+        treeroot = join(self.tmpdir, 'rootparent')
+        os.makedirs(treeroot)
+        pto = patch.fromfile(join(TESTS, '08create/08create.patch'))
+        pto.apply(strip=0, root=treeroot)
+        self.assertTrue(os.path.exists(os.path.join(treeroot, 'created')))
+
+    def test_delete_file(self):
+        treeroot = join(self.tmpdir, 'rootparent')
+        shutil.copytree(join(TESTS, '09delete'), treeroot)
+        pto = patch.fromfile(join(TESTS, '09delete/09delete.patch'))
+        pto.apply(strip=0, root=treeroot)
+        self.assertFalse(os.path.exists(os.path.join(treeroot, 'deleted')))
+
 
 class TestHelpers(unittest.TestCase):
     # unittest setting