This bug was reported by Yann Dirson, and results in an 'Error:
expected boolean value but got ""' dialog when scrolling to the bottom
of the graph under some circumstances. The issue is that git-rev-list
isn't outputting all the boundary commits when it is asked for commits
affecting only certain files. We already cope with that by adding the
missing boundary commits in addextraid, but there we weren't adding a
0 to the end of the commitlisted list when we added the extra id to
the end of the displayorder list.
This fixes it by appending 0 to commitlisted in addextraid, thus keeping
commitlisted and displayorder in sync.
Signed-off-by: Paul Mackerras <paulus@samba.org>
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>
- don't re-read refs when switching views, it's too slow; just do
it if the user did File->Update
- make the view menu use the uifont
- if we have a graph line selected, unselect it before changing the view
- if a row is selected and appears in the new view, but we have to
read in the new view, select that row when we come across it
- if no row was previously selected, or if we don't find the previously
selected row in the new view, select the first row
Signed-off-by: Paul Mackerras <paulus@samba.org>
If a view is selected it will now just update that view.
Also fixed a few other things - if you switch away from a view while
gitk is still reading it in, then switch back, gitk will re-read it
from scratch. We now re-read the references when switching views.
If something was selected before a view change, and we need to read
in the new view, we now select the previously-selected commit when
we come across it.
Fixed a bug in setting of rowrangelist plus a couple of other minor
things.
Signed-off-by: Paul Mackerras <paulus@samba.org>
This makes the font used in the UI elements of gitk configurable in the
same way the other fonts are. The default fonts used in the Xft build of
tk8.5 are particularily horrific, making this change more important
there.
Signed-off-by: Keith Packard <keithp@neko.keithp.com>
Acked-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Paul Mackerras <paulus@samba.org>
For some reason, the Cygwin Tcl's `exec' command has trouble running
scripts. Fix this by using the C `git' wrapper. Other GIT programs run
by gitk are written in C already, so we don't need to incur a
performance hit of going via the wrapper (which I'll bet isn't pretty
under Cygwin).
Signed-off-by: Mark Wooding <mdw@distorted.org.uk>
Acked-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Paul Mackerras <paulus@samba.org>
For a keyboard addict like me some keys are still missing from
gitk. Especially a key to select a commit when no commit is selected,
like just after startup. While we're at it, complete the bindings for
moving the view seperately from the selected line. Currently, the up
and down keys act on the selected line while pageup and pagedown act
on the commits viewed.
The idea is to have to normal keys change the selected line:
- Home selects first commit
- End selects last commit
- Up selects previous commit
- Down selects next commit
- PageUp moves selected line one page up
- PageDown moves selected line one page down
...and together with the Control key, it moves the commits view:
- Control-Home views first page of commits
- Control-End views last page of commits
- Control-Up moves commit view one line up
- Control-Down moves commit view one line down
- Control-PageUp moves commit view one page up
- Control-PageDown moves commit view one page down
Signed-off-By: Rutger Nijlunsing <gitk@tux.tmfweb.nl>
and with some cleanups and simplifications...
Signed-off-by: Paul Mackerras <paulus@samba.org>
Suggested by Paul Schulz. I made it a separate entry under the Help
menu rather than putting it in the About box, though.
Signed-off-by: Paul Mackerras <paulus@samba.org>
This patch allows you to enter a head name in the SHA1 id: field.
It also removes some unnecessary global declarations.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
With this, gitk can know about the graphs for multiple sets of files
and directories of interest. Each set of files/dirs and its graph is
called a "view". There is always the "All files" view, which is the
complete graph showing all commits. If files or dirs are specified
on the command line, a "Command line" view is automatically created.
Users can create new views and switch between them, and can delete
any view except the "All files" view.
This required a bit of reengineering. In particular, some more things
that were arrays have now become lists. The idrowranges array is still
used while the graph is being laid out, but for rows that have been laid
out we use the rowrangelist list instead. The cornercrossings and
crossings arrays no longer exist, and instead we compute the crossings
when needed (in assigncolor).
Still to be done: make the back/forward buttons switch views as necessary;
make the updatecommits function work right; preserve the selection if
possible when the new view has to be read in; fix the case when the user
switches away from the current view while we are still reading it in
and laying it out; further optimizations.
Signed-off-by: Paul Mackerras <paulus@samba.org>
This will make it easier to switch between views efficiently, and
turns out to be slightly faster as well.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Instead of adding extra padding to create a vertical line segment at
the lower end of a line that has an arrow, this now just draws a very
short vertical line segment at the lower end. This alternative
workaround for the Tk8.4 behaviour (not drawing arrows on diagonal
line segments) doesn't have the problem of making the graph very wide
when people do a lot of merges in a row (hi Junio :).
Signed-off-by: Paul Mackerras <paulus@samba.org>
When I made drawlineseg responsible for drawing the link to the first
child rather than drawparentlinks, that meant that the right-most X
value computed by drawparentlinks didn't include those first-child
links, and thus the first-child link could go over the top of the
commit headline. This fixes it.
Signed-off-by: Paul Mackerras <paulus@samba.org>
With this we run git-diff-tree on a commit even if we think it has
no parents, either because it really has no parents or because it
is a boundary commit. This means that gitk shows the diff for a
boundary commit when it is selected.
Signed-off-by: Paul Mackerras <paulus@samba.org>
With this, we can show the boundary (open-circle) commits immediately
after their last child, which looks much better than putting all the
boundary commits at the bottom of the graph.
Signed-off-by: Paul Mackerras <paulus@samba.org>
The first was a simple typo where I put $yc instead of [yc $row].
The second was that I broke the logic for keeping up with fast
movement through the commits, e.g. when you select a commit and then
press down-arrow and let it autorepeat. That got broken when I
changed the merge diff display to use git-diff-tree --cc.
Signed-off-by: Paul Mackerras <paulus@samba.org>
The point where the line for a parent joins to the first child
shown is visually different from the lines to the other children,
because the line doesn't branch, but terminates at the child.
Because of this, we now treat the first child a little differently
in the optimizer, and we draw its link in drawlineseg rather
than drawparentlinks. This improves the appearance of the graph.
Signed-off-by: Paul Mackerras <paulus@samba.org>
It seems Tk 8.4 can't draw arrows on diagonal line segments. This
adds code to the optimizer to make the last bit of a line go vertically
before being terminated with an arrow pointing downwards, so that
it will be drawn correctly by Tk 8.4.
Signed-off-by: Paul Mackerras <paulus@samba.org>
If the user is doing a find in files or patches, which changed the
cursor to a watch, don't change it back to a pointer when we reach
the end of laying out the graph.
Signed-off-by: Paul Mackerras <paulus@samba.org>
This turns out to be slightly simpler and faster, and will make
things a little easier when we do multiple view support.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Lines in a diff beginning with --- or +++ were not being displayed
at all. Thanks to Robert Fitzsimons for pointing out the obvious
fix, that lines beginning with --- or +++ are only to be suppressed
in the diff header. I also took the opportunity to replace a regexp
call with a couple of string compare calls, which should be faster.
Signed-off-by: Paul Mackerras <paulus@samba.org>
The error popup window can be now closed not only by clicking
the button, but also by pressing Return.
Signed-Off-By: Martin Mares <mj@ucw.cz>
Signed-off-by: Paul Mackerras <paulus@samba.org>
If you clicked on a line, so that it was drawn double-thickness,
and then scrolled to bring on-screen a child that hadn't previously
been drawn, the lines from it to the selected line were drawn
single-thickness. This fixes it so they are drawn double-thickness.
This also removes an unnecessary setting of phase in drawrest.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Now we don't parse the commits as we are reading them, we just put
commit data on a list as a blob, and instead parse the commit when
we need the various parts of it, such as when a commit is drawn on
the canvas. This makes searching a bit more interesting: now we
scan through the commit blobs doing a string or regexp match to find
commits that might match, then for those that might match, we parse
the commit info (if it isn't already parsed) and do the matching
for the various fields as before.
Signed-off-by: Paul Mackerras <paulus@samba.org>
This rearranges the code a little to eliminate some procedure calls
and reduce the number of globals accessed. It makes rowidlist and
rowoffsets lists rather than arrays, and removes the lineid array,
since $lineid($l) was the same as [lindex $displayorder $l], and the
latter is a little faster.
Signed-off-by: Paul Mackerras <paulus@samba.org>
This just does the simple thing of resetting everything, reading all
the commits, and redoing the whole layout from scratch. Hopefully
things are now fast enough that this simple approach is acceptable.
Also, this fits in better with future plans for adding the ability
to restrict the tree to just a few files and then expand back to
the whole tree.
Signed-off-by: Paul Mackerras <paulus@samba.org>
This is a new version of gitk which is much faster and has much better
graph layout. It achieves the speed by only drawing the parts of the
canvases that are actually visible. It also draws the commits in the
order that git-rev-list produces them, so if you use -d, you need to
have a recent enough git-rev-list that understands the --date-order
flag.
Signed-off-by: Paul Mackerras <paulus@samba.org>
It was broken by the change to supply just the child id to
git-diff-tree rather than both child and parent.
Signed-off-by: Paul Mackerras <paulus@samba.org>
This replaces a lot of code that used the result from several 2-way
diffs to generate a combined diff for a merge. Now we just use
git-diff-tree --cc and colorize the output a bit, which is a lot
simpler, and has the enormous advantage that if the diff doesn't
show quite what someone thinks it should show, I can deflect the
blame to someone else. :)
Signed-off-by: Paul Mackerras <paulus@samba.org>
Apparently this simplifies things for the parser/compiler and makes
it go slightly faster (since without the braces, it potentially has
to do two levels of substitutions rather than one).
Signed-off-by: Paul Mackerras <paulus@samba.org>
This uses a table of encoding names and aliases distilled from
http://www.iana.org/assignments/character-sets plus some heuristics
to convert standard encoding names to ones that Tcl recognizes.
Signed-off-by: Paul Mackerras <paulus@samba.org>
This should be more robust in the case that some does "Update" before
the initial drawing is finished. It also avoids having to reset the
list of children for each commit and reconstruct it.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Update will redraw the commits if any commits have been added to any
of the selected heads. The new commits appear on the top.
Signed-off-by: Sven Verdoolaege <skimo@kotnet.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
There is a lot more that could be put in, such as a selector for
the font family etc., but this is a start.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Hardcoding "utf-8" in the script breaks projects that use local
encoding, so allow setting i18n.commitEncoding.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Paul Mackerras <paulus@samba.org>
The change in 8b7e5d76e8, which makes
a couple of git-diff-tree calls supply only one id rather than two,
fixes the display when showing what a single commit did with dense
revlists, but broke the diff this->selected and diff selected->this
right-click menu functions.
Yann Dirson pointed this out and had a patch that fixed the diff
menu functions by passing a "singlecommit" flag around. This fixes
it a bit differently, by making the ids and diffids variables be
either a single id, in the case of showing what a commit did, or
{oldid newid}, in the case of the diff menu functions. That way
we can just pass $ids to git-diff-tree as is. Most of the changes
in fact are just reversing the order of ids in $ids and $diffids,
because they used to be {child parent}, but git-diff-tree requires
old id before new id.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Add gitencoding variable and set it to "utf-8". Use it for converting
git-rev-list output.
Signed-off-by: Pavel Roskin <proski@gnu.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
It has a fatal flaw in that it only handles timezones that are a
multiple of an hour. It's really only needed with Tk8.5, where
the clock format command has been reimplemented in Tcl and is much
slower than in Tk8.4.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Commits that weren't read from git-rev-list, i.e. the ones displayed
with an open circle, were displayed incorrectly: the headline was
null if there was only one line, and the commit comment was put all
on one line. Also, the terminal commits weren't displayed when -r
was used.
Signed-off-by: Paul Mackerras <paulus@samba.org>
gitk switched to use git-diff-tree with one argument in gettreediffs and
getblobdiffs. git-diff-tree with one argument outputs commit ID in from
of the patch. This causes an empty line after "Comments" in the lower
right pane. Also, the diff in the lower left pane has the commit ID,
which is useless there.
This patch makes git use the newly added -no-commit-id option for
git-diff-tree to suppress commit ID. It also removes the p variable in
both functions, since it has become useless after switching to the
one-argument invocation for git-diff-tree.
Signed-off-by: Pavel Roskin <proski@gnu.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
Hovering over a line in gitk displays the commit one-liner in a
box, but the text usually overflows the box. The box size is
computed with a specified font, so this patch sets the text font
as well.
Signed-off-by: Frank Sorenson <frank@tuxrocks.com>
Signed-off-by: Junio C Hamano <junkio@cox.net>
Instead of reading refs/heads/* and refs/tags/* files ourselves
and missing files in subdirectories of heads/ and tags/, use
ls-remote on local repository and grab all of them. This lets us
also remove the procedure readotherrefs.
Signed-off-by: Junio C Hamano <junkio@cox.net>
The -r flag means "rev-list order", i.e. just display the commits
in the order they come from git-rev-list.
The speedups include:
- don't process the whole commit line-by-line, only the header
- don't convert dates when reading the commits, rather do it when
needed
- don't do the $canv delete lines.$id in drawlines when drawing the
graph initially (it was taking a lot of the total time)
- cache the date conversion for each hour (more important with tk8.5,
since [clock format] is a lot slower in 8.5 than in 8.4).
Signed-off-by: Paul Mackerras <paulus@samba.org>
To generate the diff for a commit, gitk used to do
git-diff-tree -p -C $p $id
(and same thing to generate filenames, except using just "-r" there) which
does actually generate the diff from the parent to the $id, exactly like
it meant to do.
However, that really sucks with --dense, where the "parent" information
has all been rewritten to point to the previous commit. The diff actually
works exactly right, but now it's the diff of the _whole_ sequence of
commits all the way to the previous commit that last changed the file(s)
that we are looking at.
And that's really not what we want 99.9% of the time, even if it may be
perfectly sensible. Not only will the diff not actually match the commit
message, but it will usually be _huge_, and all of it will be totally
uninteresting to us, since we were only interested in a particular set of
files.
It also doesn't match what we do when we write the patch to a file.
So this makes gitk just show the diff of _that_ commit.
We might even want to have some way to limit the diff to only the
filenames we're interested in, but it's often nice to see what else
changed at the same time, so that's secondary.
The merge diff handling is left alone, although I think that should also
be changed to only look at what that _particular_ merge did, not what it
did when compared to the faked-out parents.
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This adds several new keybindings to allow history and selectline
navigation. I basically added Opera-like history traversal, as well
as left-right-cursor history traversal and vi-like motion commands.
Signed-off-by: Robert Suetterlin <robert@mpe.mpg.de>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This just displays the result of git-cat-file on the tag in the
details pane. If the tag is a "direct" tag (the tag file contains
the SHA1 ID of a commit rather than a tag), we show the tag name
and SHA1 ID.
These are features requested by Junio. Any plain file under .git/refs
whose contents start with 40 hex characters is taken as a reference
and displayed like a head but with a light blue background (unless it
is in .git/refs/tags or .git/refs/heads, in which case it is displayed
as before). There is now a "Reread references" menu item in the File
menu which re-reads all the plain files under .git/refs and redisplays
any references that have changed.
With --parents, git-rev-list gives us the list of parents on the
first line of each commit. We use that rather than looking for
the parent: lines in the commit body, since this way we get to
know about the grafts for free.
When the graph gets too wide (as defined by the maxwidth variable,
which can be set in ~/.gitk), we can now terminate graph lines with
an arrow pointing downwards, and reintroduce them later with an
arrow pointing upwards when we need them. This makes the graph much
less cluttered on large repositories such as the linux kernel.
Unfortunately this has made it slower; it takes about 10 seconds
user time on the linux-2.6 repository on my machine now, compared
to 6 seconds before. I'll have to work on optimizing that. Also
on the todo list are making the arrow heads active (so if you click
on them you jump to the other end) and improving the placement of
the null entry.
The previous commit improved performance a lot but also meant that
we waited longer to see something drawn. This refines the heuristics
for when to call update so that (1) when we have finished processing
a bufferfull of information from git-rev-list, we call update if
enough time has elapsed, regardless of how many commits we've drawn,
and (2) the number of commits drawn between updates scales with the
total number of commits drawn: 1 for 1-99 commits, 10 for 100-9999
commits, or 100 for >= 10000 commits.
On a large repository with > 60,000 commits, each call to the Tk
update primitive (which gives Tk a chance to respond to events and
redraw the screen) was taking up to 0.2 seconds. Because the logic
was to call update after drawing a commit if 0.1 seconds had passed
since the last update call, we were calling it for every commit,
which was slowing us down enormously. Now we also require that we
have drawn 100 commits since the last update (as well as it being
at least 0.1 seconds since the last update). Drawing 100 commits
takes around 0.1 - 0.2 seconds (even in this large repo) on my G5.
This adds "Child: " lines to the commit window, which tells what children
a commit has.
It also cleans things up: it marks the text widget as no-wrap, which means
that it doesn't need to truncate the commit description arbitrarily by
hand. Also, the description itself is now done by a common helper routine
that handles both the parent and the children.
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Now the history remembers when we have clicked on a graph line
and when we have asked for a diff between two commits, as well
as when we have displayed a commit.
The display when you click on a graph line now uses clickable
SHA1 IDs instead of the embedded "Go" buttons. Also made the
IDs clickable in the header for a diff between two commits.
This adds a useful "Parent:" line to the git commit information window.
It looks something like this (from the infamous octopus merge):
Author: Junio C Hamano <junkio@cox.net> 2005-05-05 16:16:54
Committer: Junio C Hamano <junkio@cox.net> 2005-05-05 16:16:54
Parent: fc54a9c30c (Update git-apply-patch-script ...)
Parent: 9e30dd7c0e (Make git-prune-script executa ...)
Parent: c4b83e618f (Do not write out new index if ...)
Parent: 660265909f (diff-cache shows differences ...)
Parent: b28858bf65 (Update diff engine for symlin ...)
Octopus merge of the following five patches.
Update git-apply-patch-script for symbolic links.
Make git-prune-script executable again.
Do not write out new index if nothing has changed.
diff-cache shows differences for unmerged paths without --cache.
Update diff engine for symlinks stored in the cache.
Signed-off-by: Junio C Hamano <junkio@cox.net>
where all the parent commit ID's are clickable, because the new lines are
added as part of the "comment" string, and thus the regular clickability
thing will match them automatically.
I think this is good. And my random-tcl-monkey-skills are clearly getting
better (although it's perfectly possible that somebody who actually knows
what he is doing would have done things differently).
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
The effect of this is that it allows Tcl to do the locale-specific
conversion of the input data to its internal unicode representation.
That means that commit messages in Russian or other languages should
be displayed correctly now (according to the locale that is in effect.)
This is based on suggestions by Jeff Epler and Linus Torvalds, but
extended so that we do the switching between the watch cursor and
the normal cursor correctly as well.
Also fixed a bug pointed out by Junio Hamano - I wasn't incrementing
the link number (duh!).
When we display the commit message in the details pane, any string
of 40 [0-9a-f] characters that corresponds to a SHA1 ID that we
know about gets turned into a clickable link, and displayed in
blue and underlined.
We now keep a history of commits that we have looked at, and we
have forward and back buttons for moving within the history list.
If the graph gets to use more than a certain percentage (default 50%)
of the width of the top-left pane, we now reduce the amount of space
allowed for each graph line. This means it doesn't look quite as
nice but you can still see the headline for the commit. (Currently
the only way to customize the percentage is to edit your ~/.gitk
file manually.)
Specifically this should fix the following errors:
wrong # args: should be "startdiff ids" (fix from Junio Hamano)
can't read "filelines(....)": no such element in array
can't unset "treepending": no such variable
Now we see if the result is quite similar to one of the parents, and
if it is, display the result as a diff from that parent. If the result
is similar to more than one parent, pick the one that it's most
similar to.
Some places assumed .git is the GIT_DIR, resulting heads and
tags not showing when it was run like "GIT_DIR=. gitk --all".
This is not a contrived example --- I rely on it to verify
my private copy of git.git repository before pushing it out.
Define a single procedure "gitdir" and use it.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Stuff that ended up in the result is shown in bold with a "+" at the
beginning of the line; stuff that didn't is in the normal font with
a "-" at the beginning of the line. The color shows which parent
the stuff was in; red for the first parent, blue for the second, then
green, purple, brown, and the rest are grey. If the result is different
from all of the parents it is shown in black (and bold).
If there is a GCA for the parents of the merge, then a file is
interesting if some parent has a version that is different from both
the child and the GCA. If there is no GCA (e.g. for a merge that
pulls in an external project) then a file is interesting if the child's
version is different from all of the parents.
Next step is to actually show the differences for the interesting
files...
We display the files where the child differs from the first parent
first in black in the file list window, followed by the second parent
in blue, and so on using different colors for each parent (provided
you don't have more than 6 parents; if you do we cycle around).
We now kick off a single git-diff-tree -r --stdin and feed it all
the commit pairs we want to know about, instead of doing a separate
git-diff-tree invocation for each.
"Files" matches the find string against each of the files modified
by each commit, and can do exact, case-ignoring or regexp matching.
"Pickaxe" uses git-diff-tree -S'string' and can only do exact
matching. I called it "pickaxe" rather than "find within patch"
since it only finds commits where the string is present in the child
but not the parents or vice versa, and "pickaxe" is what the author
of that feature calls it.
This just invokes git-diff-tree. Also changed the readonly entry
widgets in the "write patch" and "generate tag" windows to have
flat relief, so it doesn't look like you should be able to modify
what's in them.
If we have a very long commit message, and we end up getting a
bufferfull of data from git-rev-list that all belongs to one commit,
we ended up throwing away the data from a previous read that should
have been included. The result was a error message about not being
able to parse the output of git-rev-list.
Also, if the git-rev-list output that we can't parse is long, only put
the first 80 chars in the error message. Otherwise we end up with an
enormous error window.
Check that $GIT_DIR (or .git, if GIT_DIR is not set) is a directory.
This means we can give a more informative error message if the user
runs gitk somewhere that isn't a git repository.
Right-click on a context row now brings up a menu allowing the user to
generate a diff between that row and the selected row. Left-click on
a graph line shows the parent and children connected by the line in
the details pane. Left-click on a circle in the graph selects that
commit. Left-click elsewhere in the graph does nothing.
When displaying a diff, the bottom-right file list box behaves
slightly differently now; instead of eliding all other files' diffs,
it now just scrolls the details pane so that the selected file's diff
starts at the top of the pane.
Since the diffs can be rather large, arrange for an update to be done
every 100ms while reading diffs.
Also removed the CVS revision keywords and bumped the version number
to 1.2.
With --header, git-rev-list gives us the contents of the commit
in-line, so we don't need to exec a git-cat-file to get it, and we
don't need the readobj command either.
Also fixed a residual problem with handling the commit that
has a parent listed twice.
This happens in the linux-2.6 tree. We draw the graph line
double-thick to show that this happened.
Also fix a bug where we got a bogus "No commit information available"
line at the end on simple repositories like this one.
