I just checked, I created my git push tree more than a year ago, but yesterday I was reminded that this technique isn’t really documented anywhere, so let me describe it.

Some background: for the LibreOffice codebase, we decided to do all micro-features directly on the master branch. This means that we typically rebase our local master branch against origin/master, then push it. The benefit of this is that code gets wider testing quickly and the commit history is not polluted with meaningless merge commits.

The problem: one drawback of the above situation is that after you pull, some changes of other developers in the lower layers may trigger a full rebuild, typically wasting about an hour of your life (or more, in case of slower machines).

Push tree is one hack to avoid this problem. Using a push tree, you have two separate repositories locally, you update your main one less regularly, and when you have a commit to push, you push it from the push tree to be able to avoid pulling in your main tree.

Here is how to do it. To set this up:

Then to use it, instead of git pull -r && git push in your master tree, do these:

(There is a trick here, given that master-push already references the original tree, you can go ahead with cherry-pick directly, without fetching branches from your master tree.)

And that’s it, you were able to push without waiting for a long rebuild!

Note: of course this technique has some drawbacks as well, so use with care. Keep in mind the followings:

Other than these, I can just recommend using a push tree, it helped me many times not to loose focus in the middle of the day. (And as we all know, pushing all your risky changes on Friday afternoon is also a bad idea. :-) )

See here for a 3.6/4.0 version of this post.

I’m posting here a few screenshots showing improvements in our DOCX filter, done in the 4.1 development cycle. In each case I’m providing a link to the test document, a screenshot showing how it looked before and how it now looks on 4.1. Click on the images to get a larger image:

If you want to try these out yourself, get a daily build and play with it! :) If something goes wrong, report it to us in the Bugzilla, so we can try fix it in the next 4.1 bugfix release. And remember, there are lots more improvements coming in LibreOffice 4.1, stay tuned!

Yesterday Novell Hungary organized SUSE Conference 2013 here at Budapest. As you can see above Andras held a LibreOffice-related presentation there — and we also ran a LibreOffice booth. As it was requested, we set up quite some (publicly available) Android demos:

About 200 visitors attended the conference, which counts as a great success in this category. :-)

This year, LibreOffice’s Hamburg hackfest happened last weekend, with more than 20 attendees. Thanks to the sponsors, we had free drink and food during the whole hackfest. ;-)

My original plan was to add support for tables inside text frames in Writer, when importing from RTF. At the end I managed to do that, though not the way I originally wanted to implement that feature. :-)

Here is how this looked with the RTF importer we inherited from OpenOffice.org (LO 3.4), and then with the new RTF import filter (LO 3.6):

Here is how this looks like in latest master, and how it should look like:

Other than that, there were a few other topics I hacked on:

You can see some photos here.

Last, but not at least, thank you Eike and Bjoern for organizing this event! :-)

The Free Software Conference and Exhibition 2013 — organized by FSF.hu — was held yesterday @ Budapest. I gave a talk about hacking on Writer file format problems (slides), this time in Hungarian.

After the talk I also held a one-hour workshop, showing how to start hacking on LO in practice:

We (with Andras Timar and Tamas Zolnai) also ran the LibreOffice booth. This year speakers got a free t-shirt and lunch, thanks for the organizers! :)

Idén is volt Balaton Maraton (a tizenhatodik, nekem a negyedik), sikerült idén is teljesíteni a szintidőt, sőt… de ne szaladjunk ennyire előre.

mso-dumper is a project that creates some — more or less human-readable — dump from binary files. Initially Kohei Yoshida developed it to dump XLS, then Thorsten Behrens added support for PPT files, finally during last November I started to add DOC support.

You may ask: why that is useful? My answer is that I spend quite some time on the import/export filters of LibreOffice Writer, and to be able to improve or fix such filters, some knowledge of the file format in question and Writer internals is needed. Regarding the file format knowledge, I find it much easier to read the specification once and implement some simple dumper based on that — than reading the specification again and again, and just trying to understand what’s going on inside a binary file using a hex editor.

To my knowledge, such a dumper for the DOC format (in particular the WW8 version of it) did not exist previously. WW8Dumper was the closest match, but that was far from complete and I found extending mso-dumper easier.

To stress-test the parser, I used get-bugzilla-attachments-by-mimetype to get all DOC attachements from the Freedesktop bugzilla, and during the last days I fixed the remaining crashes (actually this is why I write this post now ;-) ). If you want to try it out you can do so by:

The idea is that on any input the dumper should not crash: instead either it should give you usable result, or in case some unhandled structure is reached, it should print a <todo> XML tag. Other than that, of course patches welcome — that said, Maxime de Roucy already contributed a patch to the DOC part of mso-dumper, thanks! :-)

A hétvégen Pécsett jártunk. Javában zajlott a Zsolnay Fesztivál, így talán az átlagosnál több ember hemzsegett az utcákon, de nem volt nyomasztó tömeg így sem. A következő helyeket érintettük:

Szombat:

Vasárnap:

Hétfő:

Szállásunk a Corso Hotel volt, akik egyből adtak egy Irány Pécs! kártyát, valamint náluk vettük meg a fenti fesztiválra is a napi belépőt, ezek után már a legtöbb helyre ingyenesen bejuthattunk.

Képek erre.

Last week was Hackweek at SUSE — below is a quick summary on what experiments did I do during that timeframe.

Múlt vasárnap (fehérvasárnap) bringázni voltunk a Pilisben. Nem mondom, hogy a végére nem fáradtam el, ez volt idén az első alkalom, hogy 100km feletti túrára mentem — de már bőven ideje volt.

A GPS track mutatja, hogy mi Budapestről mentünk, a társaság másik fele pedig Szentendréig HÉV-vel, és ott csatlakoztak hozzánk. Onnantól pedig a Dömör-kapu, Pilismarót, Két-bükkfa-nyereg, Dobogókő útvonalat követtük.

A kmóra a következőket mérte:

A túrán használtam először hosszútávon a nyári (nem havas, stb) időkre szánt Schwalbe Silento külsőket, egyelőre meg vagyok velük elégedve.