index.reset: updated parameter docs, but most importantly, the method now has better testing for the use of paths during reset. The IndexFile now implements this on its own, which also allows for something equivalent to git-reset --hard -- <paths>, which is not possible in the git command for some probably very good reason

Author: Byron

lib/git/index/base.py

@@ -1061,41 +1061,45 @@ def reset(self, commit='HEAD', working_tree=False, paths=None, head=False, **kwa
 			but if True, this method behaves like HEAD.reset.
 			
 		:param paths: if given as an iterable of absolute or repository-relative paths,
-			only these will be reset to their state at the given commit'ish
+			only these will be reset to their state at the given commit'ish.
+			The paths need to exist at the commit, otherwise an exception will be 
+			raised.
 
 		:param kwargs:
 			Additional keyword arguments passed to git-reset
 
 		:return: self """
-		# currently we have to use the git command to set the working copy.
-		# Otherwise we can use our own one
-		if working_tree:
-			cur_head = self.repo.head
-			prev_commit = cur_head.commit
-			
-			cur_head.reset(commit, index=True, working_tree=working_tree, paths=paths, **kwargs)
-			
-			# put the head back, possibly
-			if not head:
-				self.repo.head.commit = prev_commit
-				
-			self._delete_entries_cache()
-		else:
-			# what we actually want to do is to merge the tree into our existing
-			# index, which is what git-read-tree does
-			# TODO: incorporate the given paths !
-			new_inst = type(self).from_tree(self.repo, commit)
+		# what we actually want to do is to merge the tree into our existing
+		# index, which is what git-read-tree does
+		new_inst = type(self).from_tree(self.repo, commit)
+		if not paths:
 			self.entries = new_inst.entries
-			self.write()
-			
-			#new_inst = type(self).new(self.repo, self.repo.commit(commit).tree)
-			#self.entries = new_inst.entries
-			#self.write()
-			# self.repo.git.update_index(ignore_missing=True, refresh=True, q=True)
-			
-			if head:
-				self.repo.head.commit = self.repo.commit(commit)
+		else:
+			nie = new_inst.entries
+			for path in paths:
+				path = self._to_relative_path(path)
+				try:
+					key = entry_key(path, 0)
+					self.entries[key] = nie[key]
+				except KeyError:
+					# if key is not in theirs, it musn't be in ours
+					try:
+						del(self.entries[key])
+					except KeyError:
+						pass
+					# END handle deletion keyerror
+				# END handle keyerror
+			# END for each path
+		# END handle paths
+		self.write()
+		
+		if working_tree:
+			self.checkout(paths=paths, force=True)
 		# END handle working tree
+		
+		if head:
+			self.repo.head.commit = self.repo.commit(commit)
+		# END handle head change
 
 		return self
 

test/git/test_index.py

@@ -599,6 +599,46 @@ def make_paths():
 
 		for filenum in range(len(paths)):
 			assert index.entry_key(str(filenum), 0) in index.entries
+			
+			
+		# TEST RESET ON PATHS
+		######################
+		arela = "aa"
+		brela = "bb"
+		afile = self._make_file(arela, "adata", rw_repo)
+		bfile = self._make_file(brela, "bdata", rw_repo)
+		akey = index.entry_key(arela, 0)
+		bkey = index.entry_key(brela, 0)
+		keys = (akey, bkey)
+		absfiles = (afile, bfile)
+		files = (arela, brela)
+		
+		for fkey in keys:
+			assert not fkey in index.entries
+		
+		index.add(files, write=True)
+		nc = index.commit("2 files committed", head=False)
+		
+		for fkey in keys:
+			assert fkey in index.entries
+		
+		# just the index
+		index.reset(paths=(arela, afile))
+		assert not akey in index.entries
+		assert bkey in index.entries
+		
+		# now with working tree - files on disk as well as entries must be recreated
+		rw_repo.head.commit = nc
+		for absfile in absfiles:
+			os.remove(absfile)
+		
+		index.reset(working_tree=True, paths=files)
+		
+		for fkey in keys: 
+			assert fkey in index.entries
+		for absfile in absfiles:
+			assert os.path.isfile(absfile)
+				
 
 	@with_rw_repo('HEAD')
 	def test_compare_write_tree(self, rw_repo):