When Subversion gets to this part of rep_read_contents, rb->len is 16384. It thinks it is then done reading the entire file, and can compare the checksum, but it's not done with the file yet.
rb->rep.expanded_size is correct at the error point, 57465. rep_read_get_baton sets rb->len to rb->rep.expanded_size, so I don't know why the value changed by the time rep_read_contents got its paws on the baton. I saw that rb->len might be getting clobbered by rep_read_content's call to build_rep_list, which has the following line of code: *expanded_size = first_rep->expanded_size; expanded_size is &rep->len. I haven't had a chance to debug this area yet, so it might be fine. I verified with sqlite3 that the rep-cache.db has the correct size (57465): $ sqlite3 /mnt/d/svnclone/db/rep-cache.db "select * from rep_cache where hash='e6291ab119036eb783d0136afccdb3b445867364'" e6291ab119036eb783d0136afccdb3b445867364|227170|153|193|57465 On Mon, Mar 5, 2018 at 6:56 PM, Myria <myriac...@gmail.com> wrote: > GMail keeps doing reply instead of reply all. I'm having to manually > add the users list back now. > > Below is the thread I sent. > > > ---------- Forwarded message ---------- > From: Myria <myriac...@gmail.com> > Date: Mon, Mar 5, 2018 at 6:37 PM > Subject: Re: SHA-1 collision in repository? > To: Philip Martin <phi...@codematters.co.uk> > > > I now know where the checksum error happens, but not why. > > svn: E200014: Checksum mismatch while reading representation: > expected: bb52be764a04d511ebb06e1889910dcf > actual: 80a10d37de91cadc604ba30e379651b3 > > It's calculating the MD5 of only the first 16 KB of the input file and > comparing against the MD5 of the entire file. The 16 KB number seems > to be SVN__STREAM_CHUNK_SIZE. > > bb52be764a04d511ebb06e1889910dcf is the MD5 of the entire file. > 80a10d37de91cadc604ba30e379651b3 is the MD5 of the first 16384 bytes. > > > On Mon, Mar 5, 2018 at 5:23 PM, Myria <myriac...@gmail.com> wrote: >> I managed to compile a subversion command line client with debugging >> information and optimizations disabled, and can reproduce the problem >> with GDB attached. >> >> Here is a backtrace at the time at which the error occurs. A few line >> numbers in stream.c will be wrong by a few lines due to a few printf's >> I added. >> >> #0 svn_checksum_mismatch_err (expected=0x7ffffffdcf00, >> actual=0x7ffffa0700a0, scratch_pool=0x7ffffa070028, >> fmt=0x7ffffc259ac0 "Checksum mismatch while reading >> representation") at subversion/libsvn_subr/checksum.c:638 >> #1 0x00007ffffc2123de in rep_read_contents (baton=0x7ffffa1f6190, >> buf=0x7ffffa1f66a8 "// <redacted>"..., len=0x7ffffffdcf88) >> at subversion/libsvn_fs_fs/cached_data.c:2062 >> #2 0x00007ffffe5645fd in svn_stream_read_full (stream=0x7ffffa1f6470, >> buffer=0x7ffffa1f66a8 "// <redacted>"..., len=0x7ffffffdcf88) >> at subversion/libsvn_subr/stream.c:193 >> #3 0x00007ffffe5653f3 in svn_stream_contents_same2 >> (same=0x7ffffffdd01c, stream1=0x7ffffa1f6470, >> stream2=0x7ffffa1f6650, pool=0x7ffffa1e0028) at >> subversion/libsvn_subr/stream.c:589 >> #4 0x00007ffffc247226 in get_shared_rep (old_rep=0x7ffffffdd188, >> fs=0x7fffff601030, rep=0x7ffffa0e20b8, >> file=0x7ffffa1e0390, offset=0, reps_hash=0x0, >> result_pool=0x7fffff5e0028, scratch_pool=0x7ffffa1e0028) >> at subversion/libsvn_fs_fs/transaction.c:2280 >> #5 0x00007ffffc247734 in rep_write_contents_close >> (baton=0x7ffffa232ff0) at subversion/libsvn_fs_fs/transaction.c:2370 >> #6 0x00007ffffe56492b in svn_stream_close (stream=0x7ffffa233140) at >> subversion/libsvn_subr/stream.c:274 >> #7 0x00007ffffe841001 in apply_window (window=0x0, >> baton=0x7ffffa1000a0) at subversion/libsvn_delta/text_delta.c:732 >> #8 0x00007ffffc2520d2 in window_consumer (window=0x0, >> baton=0x7fffff5f1ab8) at subversion/libsvn_fs_fs/tree.c:2935 >> #9 0x00007ffffe8405ef in svn_txdelta_run (source=0x7fffff5f1a18, >> target=0x7fffff5f1298, >> handler=0x7ffffc25209f <window_consumer>, >> handler_baton=0x7fffff5f1ab8, checksum_kind=svn_checksum_md5, >> checksum=0x7ffffffdd458, cancel_func=0x0, cancel_baton=0x0, >> result_pool=0x7fffff5e0028, >> scratch_pool=0x7fffff5e0028) at subversion/libsvn_delta/text_delta.c:454 >> #10 0x00007ffffee98a57 in svn_wc__internal_transmit_text_deltas >> (tempfile=0x0, >> new_text_base_md5_checksum=0x7ffffffdd5b0, >> new_text_base_sha1_checksum=0x7ffffffdd5b8, db=0x7fffff6c17d8, >> local_abspath=0x7fffff672d08 >> "/mnt/d/svntest/repository/directory/Redacted.cpp", >> fulltext=0, editor=0x7fffff673700, file_baton=0x7fffff510110, >> result_pool=0x7fffff6c0028, >> scratch_pool=0x7fffff5e0028) at subversion/libsvn_wc/adm_crawler.c:1109 >> #11 0x00007ffffee98d68 in svn_wc_transmit_text_deltas3 >> (new_text_base_md5_checksum=0x7ffffffdd5b0, >> new_text_base_sha1_checksum=0x7ffffffdd5b8, wc_ctx=0x7fffff6c17c0, >> local_abspath=0x7fffff672d08 >> "/mnt/d/svntest/repository/directory/Redacted.cpp", >> fulltext=0, editor=0x7fffff673700, file_baton=0x7fffff510110, >> result_pool=0x7fffff6c0028, >> scratch_pool=0x7fffff5e0028) at subversion/libsvn_wc/adm_crawler.c:1199 >> #12 0x00007fffff18eb12 in svn_client__do_commit ( >> base_url=0x7fffff6142c0 "file:///mnt/d/svntest/repository/directory", >> commit_items=0x7fffff672c48, editor=0x7fffff673700, >> edit_baton=0x7fffff6300a0, >> notify_path_prefix=0x7fffff672900 "/mnt/d/svntest/repository", >> sha1_checksums=0x7ffffffdd750, >> ctx=0x7fffff6c16f0, result_pool=0x7fffff6c0028, >> scratch_pool=0x7fffff650028) >> at subversion/libsvn_client/commit_util.c:1920 >> #13 0x00007fffff18a5f9 in svn_client_commit6 (targets=0x7fffff670a18, >> depth=svn_depth_infinity, keep_locks=0, >> keep_changelists=0, commit_as_operations=1, >> include_file_externals=0, include_dir_externals=0, >> changelists=0x7fffff6c0780, revprop_table=0x0, >> commit_callback=0x42c6a0 <svn_cl__print_commit_info>, >> commit_baton=0x0, ctx=0x7fffff6c16f0, pool=0x7fffff6c0028) at >> subversion/libsvn_client/commit.c:901 >> #14 0x000000000040b744 in svn_cl__commit (os=0x7fffff6c0520, >> baton=0x7ffffffddc60, pool=0x7fffff6c0028) >> at subversion/svn/commit-cmd.c:171 >> #15 0x000000000042b351 in sub_main (exit_code=0x7ffffffddf3c, argc=5, >> argv=0x7ffffffde038, pool=0x7fffff6c0028) >> at subversion/svn/svn.c:3041 >> #16 0x000000000042b5ee in main (argc=5, argv=0x7ffffffde038) at >> subversion/svn/svn.c:3126 >>
