[vtk-developers] Strange repo happenings with vtkOpenGLProjectedTetrahedraMapper

[Brad King]

On 12/22/2011 8:42 AM, Bill Lorensen wrote:
> If I do a git log on the vtkOpenGLProjectedTetrahedraMappe.cxx file I
> don't see your commits or mine.

The other part of this thread identified the vtkstd changes.
I'll follow up with why your commit (49c1f9de) is not shown by:

  $ git log 49c1f9de~1..31ec9251 -- \
    VolumeRendering/vtkOpenGLProjectedTetrahedraMapper.cxx

The command tells Git to start at commit 31ec9251 and walk back looking
for commits that change the given file.  When Git comes to the incorrect
merge commit 174c39e8 it sees that the file in the commit is identical
to one of its parents.  Therefore it assumes that the content in the file
as of the merge commit can be fully explained by the history of the one
parent in which it is identical.  It follows only that parent and prunes
out the history from the other parent.  Your commit only appears in the
pruned side of history so it gets skipped.

The above behavior is an optimization that does the right thing in the
case that merges were done correctly.  One can use the "--full-history"
option to disable the behavior.  The following command shows your commit:

  $ git log 49c1f9de~1..31ec9251 --full-history -- \
    VolumeRendering/vtkOpenGLProjectedTetrahedraMapper.cxx

-Brad