graphmod: use revsets internally Thanks for the idea and most of the implementation to Klaus Koch Backs revisions() and filerevs() with DAG walker which can iterate through arbitrary list of revisions instead of strict one by one iteration from start to stop. When a gap occurs in a revisions (i.e. in file log), the next topological parent within the revset is searched and the connection to it is printed in the ascii graph. File graph can draw sometimes more connections than previous version, because graph is produced according to the revset, not according to a file's filelog. In case the graph contains several branches where the left parent is null, the graphs for each are printed sequentially, not in parallel as it was a case earlier (see for example the graph for README in hg-dev).