Re: git-diff-tree rename detection bug

On 9/14/05, Junio C Hamano [off-list ref] wrote:

Wayne Scott [off-list ref] writes:

quoted

Look at the diffs between ad6571a78ac74e9fa27e581834709067dba459af and
it's parent with and without rename detection enabled.  (In linux-2.6
git tree)

quoted

Notice how the the fact that include/asm-ppc64/termios.h is
deleted gets lost?  Looks broken to me.

I suspect that what is deleted is not asm-ppc64/termios.h but
asm-ppc/termios.h.  The below is an output without grep which
seems to confuse things.

$ git-diff-tree -r -M ad6571a78ac74e9fa27e581834709067dba459af |
  sed -ne 's/^.* \([AMCRDU]\)/\1/p'
R092    include/asm-ppc64/mman.h        include/asm-powerpc/mman.h
R097    include/asm-ppc64/termbits.h    include/asm-powerpc/termbits.h
R098    include/asm-ppc64/termios.h     include/asm-powerpc/termios.h
D       include/asm-ppc/mman.h
D       include/asm-ppc/termbits.h
D       include/asm-ppc/termios.h

$ git-diff-tree -r ad6571a78ac74e9fa27e581834709067dba459af |
  sed -ne 's/^.* \([AMCRDU]\)/\1/p'
A       include/asm-powerpc/mman.h
A       include/asm-powerpc/termbits.h
A       include/asm-powerpc/termios.h
D       include/asm-ppc/mman.h
D       include/asm-ppc/termbits.h
D       include/asm-ppc/termios.h
D       include/asm-ppc64/mman.h
D       include/asm-ppc64/termbits.h
D       include/asm-ppc64/termios.h

The first 3 A and last 3 D are accounted for in the -M output as
renames from asm-ppc64 to asm-powerpc.  Middle 3 D from asm-ppc
are shown in the -M output.  So I do not think we are losing
anything.  Am I missing something?

Odd.  I get the same answer on my x86 box:
$ git-diff-tree -r -M ad6571a78ac74e9fa27e581834709067dba459af |   sed
-ne 's/^.* \([AMCRDU]\)/\1/p'
R092    include/asm-ppc64/mman.h        include/asm-powerpc/mman.h
R097    include/asm-ppc64/termbits.h    include/asm-powerpc/termbits.h
R098    include/asm-ppc64/termios.h     include/asm-powerpc/termios.h
D       include/asm-ppc/mman.h
D       include/asm-ppc/termbits.h
D       include/asm-ppc/termios.h

But here is the output on my quad xeon running in 64-bit mode: (fedora core 2)

$ git-diff-tree -r -M ad6571a78ac74e9fa27e581834709067dba459af |   sed
-ne 's/^.* \([AMCRDU]\)/\1/p'
R092    include/asm-ppc64/mman.h        include/asm-powerpc/mman.h
R097    include/asm-ppc64/termbits.h    include/asm-powerpc/termbits.h
A       include/asm-powerpc/termios.h
D       include/asm-ppc/mman.h
D       include/asm-ppc/termbits.h
D       include/asm-ppc/termios.h

This is the same version of git both rebuilt just for this test.

However, I noticed a whole collection of errors from valgrind when I
run this command line:

==13457== Invalid read of size 4
==13457==    at 0x805402C: locate_rename_dst (diffcore-rename.c:28)
==13457==    by 0x805464B: diffcore_rename (diffcore-rename.c:356)
==13457==    by 0x805249D: diffcore_std (diff.c:1093)
==13457==    by 0x8049B48: call_diff_flush (diff-tree.c:273)
==13457==    by 0x804A225: diff_tree_sha1_top (diff-tree.c:298)
==13457==    by 0x804A30B: diff_tree_commit (diff-tree.c:363)
==13457==    by 0x804A884: main (diff-tree.c:551)
==13457==  Address 0x1BBD781C is 20 bytes inside a block of size 71 free'd
==13457==    at 0x1B9003C3: free (vg_replace_malloc.c:235)
==13457==    by 0x805205B: diff_free_filepair (diff.c:775)
==13457==    by 0x805422A: diffcore_rename (diffcore-rename.c:415)
==13457==    by 0x805249D: diffcore_std (diff.c:1093)
==13457==    by 0x8049B48: call_diff_flush (diff-tree.c:273)
==13457==    by 0x804A225: diff_tree_sha1_top (diff-tree.c:298)
==13457==    by 0x804A30B: diff_tree_commit (diff-tree.c:363)
==13457==    by 0x804A884: main (diff-tree.c:551)
==13457== 
==13457== Invalid read of size 1
==13457==    at 0x1B90140D: strcmp (mac_replace_strmem.c:332)
==13457==    by 0x8054038: locate_rename_dst (diffcore-rename.c:28)
==13457==    by 0x805464B: diffcore_rename (diffcore-rename.c:356)
==13457==    by 0x805249D: diffcore_std (diff.c:1093)
==13457==    by 0x8049B48: call_diff_flush (diff-tree.c:273)
==13457==    by 0x804A225: diff_tree_sha1_top (diff-tree.c:298)
==13457==    by 0x804A30B: diff_tree_commit (diff-tree.c:363)
==13457==    by 0x804A884: main (diff-tree.c:551)
==13457==  Address 0x1BBD7830 is 40 bytes inside a block of size 71 free'd
==13457==    at 0x1B9003C3: free (vg_replace_malloc.c:235)
==13457==    by 0x805205B: diff_free_filepair (diff.c:775)
==13457==    by 0x805422A: diffcore_rename (diffcore-rename.c:415)
==13457==    by 0x805249D: diffcore_std (diff.c:1093)
==13457==    by 0x8049B48: call_diff_flush (diff-tree.c:273)
==13457==    by 0x804A225: diff_tree_sha1_top (diff-tree.c:298)
==13457==    by 0x804A30B: diff_tree_commit (diff-tree.c:363)
==13457==    by 0x804A884: main (diff-tree.c:551)
==13457== 
==13457== Invalid read of size 1
==13457==    at 0x1B901423: strcmp (mac_replace_strmem.c:332)
==13457==    by 0x8054038: locate_rename_dst (diffcore-rename.c:28)
==13457==    by 0x805464B: diffcore_rename (diffcore-rename.c:356)
==13457==    by 0x805249D: diffcore_std (diff.c:1093)
==13457==    by 0x8049B48: call_diff_flush (diff-tree.c:273)
==13457==    by 0x804A225: diff_tree_sha1_top (diff-tree.c:298)
==13457==    by 0x804A30B: diff_tree_commit (diff-tree.c:363)
==13457==    by 0x804A884: main (diff-tree.c:551)
==13504== Invalid read of size 4
==13504==    at 0x805402C: locate_rename_dst (diffcore-rename.c:28)
==13504==    by 0x805464B: diffcore_rename (diffcore-rename.c:356)
==13504==    by 0x805249D: diffcore_std (diff.c:1093)
==13504==    by 0x8049B48: call_diff_flush (diff-tree.c:273)
==13504==    by 0x804A225: diff_tree_sha1_top (diff-tree.c:298)
==13504==    by 0x804A30B: diff_tree_commit (diff-tree.c:363)
==13504==    by 0x804A884: main (diff-tree.c:551)
==13504==  Address 0x1BBD781C is 20 bytes inside a block of size 71 free'd
==13504==    at 0x1B9003C3: free (vg_replace_malloc.c:235)
==13504==    by 0x805205B: diff_free_filepair (diff.c:775)
==13504==    by 0x805422A: diffcore_rename (diffcore-rename.c:415)
==13504==    by 0x805249D: diffcore_std (diff.c:1093)
==13504==    by 0x8049B48: call_diff_flush (diff-tree.c:273)
==13504==    by 0x804A225: diff_tree_sha1_top (diff-tree.c:298)
==13504==    by 0x804A30B: diff_tree_commit (diff-tree.c:363)
==13504==    by 0x804A884: main (diff-tree.c:551)
==13504== 
==13504== Invalid read of size 1
==13504==    at 0x1B90140D: strcmp (mac_replace_strmem.c:332)
==13504==    by 0x8054038: locate_rename_dst (diffcore-rename.c:28)
==13504==    by 0x805464B: diffcore_rename (diffcore-rename.c:356)
==13504==    by 0x805249D: diffcore_std (diff.c:1093)
==13504==    by 0x8049B48: call_diff_flush (diff-tree.c:273)
==13504==    by 0x804A225: diff_tree_sha1_top (diff-tree.c:298)
==13504==    by 0x804A30B: diff_tree_commit (diff-tree.c:363)
==13504==    by 0x804A884: main (diff-tree.c:551)
==13504==  Address 0x1BBD7830 is 40 bytes inside a block of size 71 free'd
==13504==    at 0x1B9003C3: free (vg_replace_malloc.c:235)
==13504==    by 0x805205B: diff_free_filepair (diff.c:775)
==13504==    by 0x805422A: diffcore_rename (diffcore-rename.c:415)
==13504==    by 0x805249D: diffcore_std (diff.c:1093)
==13504==    by 0x8049B48: call_diff_flush (diff-tree.c:273)
==13504==    by 0x804A225: diff_tree_sha1_top (diff-tree.c:298)
==13504==    by 0x804A30B: diff_tree_commit (diff-tree.c:363)
==13504==    by 0x804A884: main (diff-tree.c:551)
==13504== 
==13504== Invalid read of size 1
==13504==    at 0x1B901423: strcmp (mac_replace_strmem.c:332)
==13504==    by 0x8054038: locate_rename_dst (diffcore-rename.c:28)
==13504==    by 0x805464B: diffcore_rename (diffcore-rename.c:356)
==13504==    by 0x805249D: diffcore_std (diff.c:1093)
==13504==    by 0x8049B48: call_diff_flush (diff-tree.c:273)
==13504==    by 0x804A225: diff_tree_sha1_top (diff-tree.c:298)
==13504==    by 0x804A30B: diff_tree_commit (diff-tree.c:363)
==13504==    by 0x804A884: main (diff-tree.c:551)
==13504==  Address 0x1BBD7831 is 41 bytes inside a block of size 71 free'd
==13504==    at 0x1B9003C3: free (vg_replace_malloc.c:235)
==13504==    by 0x805205B: diff_free_filepair (diff.c:775)
==13504==    by 0x805422A: diffcore_rename (diffcore-rename.c:415)
==13504==    by 0x805249D: diffcore_std (diff.c:1093)
==13504==    by 0x8049B48: call_diff_flush (diff-tree.c:273)
==13504==    by 0x804A225: diff_tree_sha1_top (diff-tree.c:298)
==13504==    by 0x804A30B: diff_tree_commit (diff-tree.c:363)
==13504==    by 0x804A884: main (diff-tree.c:551)
==13504== 

Perhaps that explains the difference.

-Wayne