22626ef4fd
Previously, if we switched away from a view before we had finished reading the git-rev-list output for it and laying out the graph, we would discard the partially-laid-out graph and reread it from scratch if we switched back to the view. With this, we preserve the state of the partially-laid-out graph in viewdata($view) and restore it if we switch back. The pipe to git-rev-list remains open but we just don't read from it any more until we switch back to that view. This also makes linesegends a list rather than an array, which turns out to be slightly faster, as well as being easier to save and restore. The `update' menu item now kills the git-rev-list process if there is one still running when we do the update. Signed-off-by: Paul Mackerras <paulus@samba.org>