How could I use git bisect to find the first GOOD commit?

Question

I have the following problem:

• the version at master works fine
• the version of the last tag before master (say last) has a bug
• a colleague needs a patch for his last revision for that certain bug

Okay. Let's ask our friend git bisect for the revision that fixed the bug:

git bisect start git bisect bad last git bisect good master 

But that's not going to work:

Some good revs are not ancestor of the bad rev.
git bisect cannot work properly in this case.
Maybe you mistake good and bad revs?

Any hints to overcome this? Did I miss something in the docs?

Answer 1

As of git 2.7, you can use the arguments --term-old and --term-new.

For instance, you can identify a problem-fixing commit thus:

git bisect start --term-new=fixed --term-old=unfixed git bisect fixed master git bisect unfixed $some-old-sha1 

As you test, say git bisect fixed or git bisect unfixed as appropriate.

Old answer, for versions of git prior to 2.7

Instead of temporarily training yourself to think that bad means good and good means bad, why not create some aliases?

In ~/.gitconfig add the following:

[alias]         bisect-fixed = bisect bad         bisect-unfixed = bisect good 

You can start identifying a problem-fixing commit thus:

$ git bisect start $ git bisect-fixed master $ git bisect-unfixed $some-old-sha1 

As you test, say git bisect-fixed or git bisect-unfixed as appropriate.