upstream/mercurial-mirror Files · mercurial/ancestor.py

patch: fix patch hunk/metdata synchronization (issue3384)...

patch: fix patch hunk/metdata synchronization (issue3384) Git patches are parsed in two phases: 1) extract metadata, 2) parse actual deltas and merge them with the previous metadata. We do this to avoid dependency issues like "modify a; copy a to b", where "b" must be copied from the unmodified "a". Issue3384 is caused by flaky code I wrote to synchronize the patch metadata with the emitted hunk: if (gitpatches and (gitpatches[-1][0] == afile or gitpatches[-1][1] == bfile)): gp = gitpatches.pop()[2] With a patch like: diff --git a/a b/c copy from a copy to c --- a/a +++ b/c @@ -1,1 +1,2 @@ a +a @@ -2,1 +2,2 @@ a +a diff --git a/a b/a --- a/a +++ b/a @@ -1,1 +1,2 @@ a +b the first hunk of the first block is matched with the metadata for the block "diff --git a/a b/c", then the second hunk of the first block is matched with the metadata of the second block "diff --git a/a b/a", because of the "or" in the code paste above. Turning the "or" into an "and" is not enough as we have to deal with /dev/null cases for each file. We I remove this broken piece of code: # copy/rename + modify should modify target, not source if gp.op in ('COPY', 'DELETE', 'RENAME', 'ADD') or gp.mode: afile = bfile because "afile = bfile" set "afile" to stuff like "b/file" instead of "a/file", and because this only happens for git patches, which afile/bfile are ignored anyway by applydiff(). v2: - Avoid a traceback on git metadata desynchronization

Martin Geisler - - Load All Authors

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      # ancestor.py - generic DAG ancestor algorithm for mercurial

      #

      # Copyright 2006 Matt Mackall <mpm@selenic.com>

      #

      # This software may be used and distributed according to the terms of the

      # GNU General Public License version 2 or any later version.

      import heapq

      def ancestor(a, b, pfunc):

          """

          Returns the common ancestor of a and b that is furthest from a

          root (as measured by longest path) or None if no ancestor is

          found. If there are multiple common ancestors at the same

          distance, the first one found is returned.

          pfunc must return a list of parent vertices for a given vertex

          """

          if a == b:

              return a

          a, b = sorted([a, b])

          # find depth from root of all ancestors

          # depth is stored as a negative for heapq

          parentcache = {}

          visit = [a, b]

          depth = {}

          while visit:

              vertex = visit[-1]

              pl = pfunc(vertex)

              parentcache[vertex] = pl

              if not pl:

                  depth[vertex] = 0

                  visit.pop()

              else:

                  for p in pl:

                      if p == a or p == b: # did we find a or b as a parent?

                          return p # we're done

                      if p not in depth:

                          visit.append(p)

                  if visit[-1] == vertex:

                      # -(maximum distance of parents + 1)

                      depth[vertex] = min([depth[p] for p in pl]) - 1

                      visit.pop()

          # traverse ancestors in order of decreasing distance from root

          def ancestors(vertex):

              h = [(depth[vertex], vertex)]

              seen = set()

              while h:

                  d, n = heapq.heappop(h)

                  if n not in seen:

                      seen.add(n)

                      yield (d, n)

                      for p in parentcache[n]:

                          heapq.heappush(h, (depth[p], p))

          def generations(vertex):

              sg, s = None, set()

              for g, v in ancestors(vertex):

                  if g != sg:

                      if sg:

                          yield sg, s

                      sg, s = g, set((v,))

                  else:

                      s.add(v)

              yield sg, s

          x = generations(a)

          y = generations(b)

          gx = x.next()

          gy = y.next()

          # increment each ancestor list until it is closer to root than

          # the other, or they match

          try:

              while True:

                  if gx[0] == gy[0]:

                      for v in gx[1]:

                          if v in gy[1]:

                              return v

                      gy = y.next()

                      gx = x.next()

                  elif gx[0] > gy[0]:

                      gy = y.next()

                  else:

                      gx = x.next()

          except StopIteration:

              return None

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				# ancestor.py - generic DAG ancestor algorithm for mercurial
				#
				# Copyright 2006 Matt Mackall <mpm@selenic.com>
				#
				# This software may be used and distributed according to the terms of the
				# GNU General Public License version 2 or any later version.

				import heapq

				def ancestor(a, b, pfunc):
				"""
				Returns the common ancestor of a and b that is furthest from a
				root (as measured by longest path) or None if no ancestor is
				found. If there are multiple common ancestors at the same
				distance, the first one found is returned.

				pfunc must return a list of parent vertices for a given vertex
				"""

				if a == b:
				return a

				a, b = sorted([a, b])

				# find depth from root of all ancestors
				# depth is stored as a negative for heapq
				parentcache = {}
				visit = [a, b]
				depth = {}
				while visit:
				vertex = visit[-1]
				pl = pfunc(vertex)
				parentcache[vertex] = pl
				if not pl:
				depth[vertex] = 0
				visit.pop()
				else:
				for p in pl:
				if p == a or p == b: # did we find a or b as a parent?
				return p # we're done
				if p not in depth:
				visit.append(p)
				if visit[-1] == vertex:
				# -(maximum distance of parents + 1)
				depth[vertex] = min([depth[p] for p in pl]) - 1
				visit.pop()

				# traverse ancestors in order of decreasing distance from root
				def ancestors(vertex):
				h = [(depth[vertex], vertex)]
				seen = set()
				while h:
				d, n = heapq.heappop(h)
				if n not in seen:
				seen.add(n)
				yield (d, n)
				for p in parentcache[n]:
				heapq.heappush(h, (depth[p], p))

				def generations(vertex):
				sg, s = None, set()
				for g, v in ancestors(vertex):
				if g != sg:
				if sg:
				yield sg, s
				sg, s = g, set((v,))
				else:
				s.add(v)
				yield sg, s

				x = generations(a)
				y = generations(b)
				gx = x.next()
				gy = y.next()

				# increment each ancestor list until it is closer to root than
				# the other, or they match
				try:
				while True:
				if gx[0] == gy[0]:
				for v in gx[1]:
				if v in gy[1]:
				return v
				gy = y.next()
				gx = x.next()
				elif gx[0] > gy[0]:
				gy = y.next()
				else:
				gx = x.next()
				except StopIteration:
				return None