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Re: segfault during merge (1.6.2)

From: Stefan Küng <tortoisesvn_at_gmail.com>
Date: Tue, 19 May 2009 07:09:44 +0200

Paul Burba wrote:
> On Mon, May 18, 2009 at 12:56 PM, Stefan Küng <tortoisesvn_at_gmail.com> wrote:
>> Hi,
>>
>> Crash report sent for TSVN:
>>
>> A segfault in subversion\libsvn_client\merge.c, function
>> remove_noop_merge_ranges(), line 5022.
>>
>> It seems that APR_ARRAY_IDX() return NULL (the changed_revs->nelts is
>> 0). But the 'ranges->nelts' in the for-loop above it has a value of two.
>>
>> This is a merge with:
>>
>> svn_client_merge_peg3(https://url/to/file,
>> Â Â Â Â revrange 1-HEAD,
>> Â Â Â Â HEAD,
>> Â Â Â Â path/to/wc/file/in/other/branch,
>> Â Â Â Â infinity,
>> Â Â Â Â TRUE,
>> Â Â Â Â FALSE,
>> Â Â Â Â FALSE,
>> Â Â Â Â FALSE,
>> Â Â Â Â "",
>> Â Â Â Â &ctx, pool);
>
> Hi Stefan,
>
> Something is odd about this report. You indicate the merge is with
> --ignore-ancestry (6th argument to svn_client_merge_peg3). This means
> that merge.c:do_file_merge, the only caller of
> remove_noop_merge_ranges, will set its local variable REMAINING_RANGES
> to a single element array:

Ups, sorry. It's the 'force' parameter that's true and the others are false.

> range.start = revision1;
> range.end = revision2;
> range.inheritable = TRUE;
> if (honor_mergeinfo)
> {
> ### --ignore-ancestry means we aren't honoring mergeinfo so we
> never enter this block
> }
>
> /* The simple cases where our remaining range is REVISION1:REVISION2. */
> if (!honor_mergeinfo || merge_b->record_only)
> {
> remaining_ranges = apr_array_make(pool, 1, sizeof(&range));
> APR_ARRAY_PUSH(remaining_ranges, svn_merge_range_t *) = &range;
> }
>
> Which in turn means that remove_noop_merge_ranges can never be called:
>
> if (!merge_b->record_only)
> {
> apr_array_header_t *ranges_to_merge = remaining_ranges;
>
> /* If we have ancestrally related sources and more than one
> range to merge, eliminate no-op ranges before going through
> the effort of downloading the many copies of the file
> required to do these merges (two copies per range). */
> if (merge_b->sources_ancestral && (remaining_ranges->nelts > 1))
> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> {
> const char *old_sess_url = NULL;
> SVN_ERR(svn_client__ensure_ra_session_url(&old_sess_url,
> merge_b->ra_session1,
> primary_url, subpool));
> SVN_ERR(remove_noop_merge_ranges(&ranges_to_merge,
> merge_b->ra_session1,
> remaining_ranges, subpool));
>
> Also, line 5022 in
> http://svn.collab.net/repos/svn/tags/1.6.2/subversion/libsvn_client/merge.c
> is:
>
> 5022 if ((! SVN_IS_VALID_REVNUM(oldest_rev)) || (min_rev < oldest_rev))

Again, so sorry. I guess I had the cursor in the wrong line when I read
the source line (VS shows the line where the cursor is on the bottom
right - I don't have line numbers enabled elsewhere).
It's line 5034 (the one with APR_ARRAY_IDX()).

Stefan

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Received on 2009-05-19 07:10:10 CEST

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