Re: Can't find the revelant commit with git-log

Am 26.01.2011 19:11, schrieb René Scharfe:

OK, regarding the second point:

Merges that have at least one parent without changes in the selected subset of files won't be displayed, not even with --full-history. That explains why removing the last path component made a difference: all the merges ended up with a version of the file that matched one of their parents, but there were other changes in the directory.

This is a feature: since the version of the file picked by the merge must have been introduced by an earlier commit (a regular one, presumably), you'll find it there anyway.

And this history simplification takes precedence over pickaxe (-S).

The patch below turns down its aggressiveness when the pickaxe is swung at the same time. Here's what it does to your use case:

	$ revs="v2.6.26..v2.6.29"
	$ opts="-Sblacklist_iommu --oneline -m --full-history"

	# This takes quite a while...
	$ git log $opts $revs | wc -l
	160

	# Without the patch:
	$ git log $opts $revs -- drivers/pci/intel-iommu.c | wc -l
	2

	# With the patch (really just its first hunk):
	$ git log $opts $revs -- drivers/pci/intel-iommu.c | wc -l
	160

	$ opts="-Sblacklist_iommu --oneline -m"

	# This takes quite a while...
	$ git log $opts $revs | wc -l
	160

	# Without the patch:
	$ git log $opts $revs -- drivers/pci/intel-iommu.c | wc -l
	0

	# With the patch:
	$ git log $opts $revs -- drivers/pci/intel-iommu.c | wc -l
	160

	$ opts="-Sblacklist_iommu --oneline"

	# This takes a bit, but not too long.
	$ git log $opts $revs | wc -l
	1

	# Without the patch:
	$ git log $opts $revs -- drivers/pci/intel-iommu.c | wc -l
	0

	# With the patch:
	$ git log $opts $revs -- drivers/pci/intel-iommu.c | wc -l
	1

The full output matches exactly if the number of lines match. That's to be expected, as the string "blacklist_iommu" only ever appears in the file drivers/pci/intel-iommu.c.

It wasn't mentioned before v2.6.26 or after v2.6.29.

There is only one regular commit, namely the initial one that introduced the function. Some merges are reported more than once, each for every parent where -S hit. 135 unique commits are reported.

-- >8 --
Subject: pickaxe: don't simplify history too much

If pickaxe is used, turn off history simplification and make sure to keep merges with at least one interesting parent.

If path specs are used, merges that have at least one parent whose files match those in the specified subset are edited out. This is good in general, but leads to unexpectedly few results if used together with pickaxe. Merges that also have an interesting parent (in terms of -S or -G) are dropped, too.

This change makes sure pickaxe takes precedence over history simplification. This means path specs won't change the results as long as they contain all the files that pickaxe turns up. E.g. these two commands now report the same single commit that added the function blacklist_iommu to the specified file in the Linux kernel repo:

   $ git log -Sblacklist_iommu v2.6.26..v2.6.29 --
   $ git log -Sblacklist_iommu v2.6.26..v2.6.29 -- drivers/pci/intel-iommu.c

Previously the second one came up empty.

Reported-by: Francis Moreau <francis.moro@gmail.com>
Signed-off-by: Rene Scharfe <rene.scharfe@lsrfire.ath.cx>
---
 revision.c                   |    5 +++++
 t/t6012-rev-list-simplify.sh |    2 ++
 2 files changed, 7 insertions(+), 0 deletions(-)