- A list of tuples indicating the edges between the current node and its

        parents.

    """

    branch_cache = {}

    def branch(rev):

        """Return branch for rev, using cache for efficiency.

        For Mercurial, always return the named branch name (which may be 'default').

        For Git, return a branch name for branch heads, otherwise None."""

        if rev not in branch_cache:

            branch_cache[rev] = repo[rev].branch

        return branch_cache[rev]

    row = []  # the ancestor revision that each column is tracking

    colors = {}  # color number for revisions - set by descendants

    obs = {}  # obsolete flag for revisions - set by descendants

    newcolor = 1  # the next available color

    for (rev, dagparents) in dag:

        # Compute row and nextrow

        if rev not in row:

            row.append(rev)  # new head

            colors[rev] = newcolor

            obs[rev] = int(repo[rev].obsolete)

            newcolor += 1

        col = row.index(rev)

        addparents = [p for p in dagparents if p not in row]

        # Add unknown parents to nextrow

        tmprow = row[:]

        tmprow[col:col + 1] = reversed(addparents) # highest revs first (to the right), dead ends last (to the left)

        # Filter old fake parents but keep new ones

        nextrow = []

        for r in tmprow:

            if r >= 0 or r in dagparents:

                nextrow.append(r)

            else:

                colors.pop(r)

                obs.pop(r)

        # Let color and obs for this rev be "inherited" by the first "parent"

        color = colors.pop(rev)

        if addparents:

            b = branch(rev)

            searching = True

            for p in reversed(addparents):

                obs[p] = int(repo[p].obsolete)

                    # This is the first parent on the same branch - inherit the color

                    colors[p] = color

                    searching = False # make sure we don't give the color away twice

                else:

                    colors[p] = newcolor

                    newcolor += 1

        # Add edges to the graph

        edges = []

        for ecol, ep in enumerate(row):

            if ep in nextrow:

                edges.append((ecol, nextrow.index(ep), colors[ep], obs[ep]))

            elif ep == rev:

                for p in dagparents:

                    edges.append((ecol, nextrow.index(p), colors[p], obs[p]))

        # Yield and move on

        closing = int(repo[rev].closesbranch)

        obsolete = int(repo[rev].obsolete)

        yield ((col, color), edges, closing, obsolete)

        row = nextrow

    def test_index_pagination_hg(self):

        self.log_user()

        #pagination

        self.app.get(url(controller='changelog', action='index',

                                    repo_name=HG_REPO), {'page': 1})

        self.app.get(url(controller='changelog', action='index',

                                    repo_name=HG_REPO), {'page': 2})

        self.app.get(url(controller='changelog', action='index',

                                    repo_name=HG_REPO), {'page': 3})

        self.app.get(url(controller='changelog', action='index',

                                    repo_name=HG_REPO), {'page': 4})

        self.app.get(url(controller='changelog', action='index',

                                    repo_name=HG_REPO), {'page': 5})

        response = self.app.get(url(controller='changelog', action='index',

                                    repo_name=HG_REPO), {'page': 6, 'size': 20})

        # Test response after pagination...

        response.mustcontain(

            """<input class="changeset_range" """

            """id="22baf968d547386b9516965ce89d189665003a31" """

            """name="22baf968d547386b9516965ce89d189665003a31" """

            """type="checkbox" value="1" />"""

        )

        response.mustcontain(

            """<span class="changeset_hash">r539:22baf968d547</span>"""

        )

    def test_index_git(self):

        self.log_user()

        response = self.app.get(url(controller='changelog', action='index',

                                    repo_name=GIT_REPO))

        response.mustcontain('''id="chg_20" class="container "''') # why no mergerow for git?

        response.mustcontain(

            """<input class="changeset_range" """

            """id="95f9a91d775b0084b2368ae7779e44931c849c0e" """

            """name="95f9a91d775b0084b2368ae7779e44931c849c0e" """

            """type="checkbox" value="1" />"""

        )

        response.mustcontain(

            """<span class="changeset_hash">r613:95f9a91d775b</span>"""

        )

        response.mustcontain("""fixing stupid typo in context for mercurial""")

#        response.mustcontain(

#            """<div id="changed_total_5e204e7583b9c8e7b93a020bd036564b1e731dae" """

#            """style="float:right;" class="changed_total tooltip" """

#            """title="Affected number of files, click to show """

#            """more details">3</div>"""

#        )

    def test_index_pagination_git(self):

        self.log_user()

        #pagination

        self.app.get(url(controller='changelog', action='index',

                                    repo_name=GIT_REPO), {'page': 1})

        self.app.get(url(controller='changelog', action='index',

                                    repo_name=GIT_REPO), {'page': 2})

        self.app.get(url(controller='changelog', action='index',

                                    repo_name=GIT_REPO), {'page': 3})

        self.app.get(url(controller='changelog', action='index',

                                    repo_name=GIT_REPO), {'page': 4})

        self.app.get(url(controller='changelog', action='index',

                                    repo_name=GIT_REPO), {'page': 5})

        response = self.app.get(url(controller='changelog', action='index',

                                    repo_name=GIT_REPO), {'page': 6, 'size': 20})

        # Test response after pagination...

        response.mustcontain(

            """<input class="changeset_range" """

            """id="636ed213f2f11ef91071b9c24f2d5e6bd01a6ed5" """

            """name="636ed213f2f11ef91071b9c24f2d5e6bd01a6ed5" """

            """type="checkbox" value="1" />"""

        )

        response.mustcontain(

            """<span class="changeset_hash">r515:636ed213f2f1</span>"""

        )

    def test_index_hg_with_filenode(self):

        self.log_user()

        response = self.app.get(url(controller='changelog', action='index',

                                    revision='tip', f_path='/vcs/exceptions.py',

                                    repo_name=HG_REPO))

        #history commits messages

        response.mustcontain('Added exceptions module, this time for real')

        response.mustcontain('Added not implemented hg backend test case')

        response.mustcontain('Added BaseChangeset class')

        # Test response...

    def test_index_git_with_filenode(self):