Re: Wrap up of Line Level History Browser [long]

Hi Bo, *

As a brief introduction to people who haven't been following, and partially answering an earlier question in another thread:

David Lang wrote:

For me it replaces a manual iterative process to find out in what ways a function was patched until it came to have its current shape:

  git-blame the area, find the most recent commit C
  while 1:
    git show C
    if that explains the code: break
    git-blame the area in C^
    find the most recent commit and call it C again

I do this a lot when a particular section of code puzzles me or seems buggy, to see if any commit message provides a reason for it. I think (but I never got good with it) the "blame parent" feature of 'git gui blame' covers a similar use-case.

All of this can now be replaced by a simple

  git log -L <range> <filename>

A good example that I did a lot of testing with:

  git log --graph be58e70d^ -L /builtin_funcname_pattern/,/^}/ diff.c

Try it. I can follow up with more examples if you're interested, but it's much more fun if you're actually looking for some explanations.

As for the project: First off, many thanks Bo for all the work you put into it. I think you planned and executed this project very well. There were some minor changes to the original drafts, but comparing the feature list from the project proposal (this is only an abstract, the real list was much longer):

} 1. Line-history (main work :-) } 2. -M/-C support } 3. Configurable context } 4. -C -C support } 5. Fuzzy matching for -M/-C } 6. Configurable display (--graph) } 7. Machine-readable output (--porcelain) } 8. Support git-log options where possible

with the feature list you posted

Bo Yang wrote:

we see that while there's still some work to be done in the -C -C area, most of the features are there. The ones that didn't make it are 5 (fuzzy matching) and to some extent 3 (context control; there is --full-line-diff). We agreed to drop 7 (--porcelain) in private conversation when we found out that gitk is already halfway ready to read --format=full output. Combined-diff style output for merges was also added to the list sometime in summer, then dropped again because of time constraints.

Next, thanks also to Jens who co-mentored. Things went very smooth despite my roughly 4 weeks of absence during the GSoC months thanks to his efforts.

Finally, I'd like to outline some of my dreams^Wfuture directions for this feature. Some of them have been promised by Bo privately, but let's not put any pressure on him now that the project is officially over.

* Support in gitk to read --format=full output (within some
  constraints maybe), thus letting us see the output more
  conveniently.

* Support in gitk to parse the -L option and pass it to the right
  git-log invocation.

* Combined-diff style output for merges.

* As Junio has suggested in a thread about the option parsing, it
  should be possible to extend this to scan history both ways, i.e.,
  "I have lines 11-19 in commit abcdef, explain how they came and
  where they went".

I think that's all for today, thanks for reading so much text.

Regards