Hi Thomas,
On Tue, 8 Oct 2019, Thomas Gummerer wrote:
> In ef283b3699 ("apply: make parse_git_diff_header public", 2019-07-11)
> the 'parse_git_diff_header' function was made public and useable by
> callers outside of apply.c.
>
> However it was missed that its (then) only caller, 'find_header' did
> some error handling, and completing 'struct patch' appropriately.
>
> range-diff then started using this function, and tried to handle this
> appropriately itself, but fell short in some cases. This in turn
> would lead to range-diff segfaulting when there are mode-only changes
> in a range.
>
> Move the error handling and completing of the struct into the
> 'parse_git_diff_header' function, so other callers can take advantage
> of it. This fixes the segfault in 'git range-diff'.
>
> Reported-by: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx>
Acked-by: Johannes Schindelin <johannes.schindelin@xxxxxx>
Ciao,
Dscho
> Signed-off-by: Thomas Gummerer <t.gummerer@xxxxxxxxx>
> ---
>
> Thanks Junio and Dscho for your reviews. I decided to lift the whole
> error handling behaviour from find_header into parse_git_diff_header,
> instead of just filling the two names with xstrdup(def_name) if
> (!old_name && !new_name && !!def_name). I think the additional
> information presented there can be useful. For example we would have
> gotten some "error: git diff header lacks filename information"
> instead of a segfault for the problem described in
> https://public-inbox.org/git/20191002141615.GB17916@xxxxxxxxxxxxxxx/T/#me576615d7a151cf2ed46186c482fbd88f9959914.
>
> Dscho, I didn't re-use your test case here as I had already written
> one, and think what I have is slightly nicer in that it follows what
> most other range-diff tests do in using the fast-exported history. It
> also expands the test coverage slightly, as we currently don't have
> any coverage of the mode-change header, but will with this test.
>
> The downside is of course that the fast export script is harder to
> understand than the test you had, at least for me, but I think the
> tradeoff of having the additional test coverage, and having it similar
> to the rest of the test script is worth it. If you strongly prefer
> your test though I'm not going to be unhappy to use that :)
>
> apply.c | 43 +++++++++++++++++++++---------------------
> t/t3206-range-diff.sh | 40 +++++++++++++++++++++++++++++++++++++++
> t/t3206/history.export | 31 +++++++++++++++++++++++++++++-
> 3 files changed, 92 insertions(+), 22 deletions(-)
>
> diff --git a/apply.c b/apply.c
> index 57a61f2881..f8a046a6a5 100644
> --- a/apply.c
> +++ b/apply.c
> @@ -1361,11 +1361,32 @@ int parse_git_diff_header(struct strbuf *root,
> if (check_header_line(*linenr, patch))
> return -1;
> if (res > 0)
> - return offset;
> + goto done;
> break;
> }
> }
>
> +done:
> + if (!patch->old_name && !patch->new_name) {
> + if (!patch->def_name) {
> + error(Q_("git diff header lacks filename information when removing "
> + "%d leading pathname component (line %d)",
> + "git diff header lacks filename information when removing "
> + "%d leading pathname components (line %d)",
> + parse_hdr_state.p_value),
> + parse_hdr_state.p_value, *linenr);
> + return -128;
> + }
> + patch->old_name = xstrdup(patch->def_name);
> + patch->new_name = xstrdup(patch->def_name);
> + }
> + if ((!patch->new_name && !patch->is_delete) ||
> + (!patch->old_name && !patch->is_new)) {
> + error(_("git diff header lacks filename information "
> + "(line %d)"), *linenr);
> + return -128;
> + }
> + patch->is_toplevel_relative = 1;
> return offset;
> }
>
> @@ -1546,26 +1567,6 @@ static int find_header(struct apply_state *state,
> return -128;
> if (git_hdr_len <= len)
> continue;
> - if (!patch->old_name && !patch->new_name) {
> - if (!patch->def_name) {
> - error(Q_("git diff header lacks filename information when removing "
> - "%d leading pathname component (line %d)",
> - "git diff header lacks filename information when removing "
> - "%d leading pathname components (line %d)",
> - state->p_value),
> - state->p_value, state->linenr);
> - return -128;
> - }
> - patch->old_name = xstrdup(patch->def_name);
> - patch->new_name = xstrdup(patch->def_name);
> - }
> - if ((!patch->new_name && !patch->is_delete) ||
> - (!patch->old_name && !patch->is_new)) {
> - error(_("git diff header lacks filename information "
> - "(line %d)"), state->linenr);
> - return -128;
> - }
> - patch->is_toplevel_relative = 1;
> *hdrsize = git_hdr_len;
> return offset;
> }
> diff --git a/t/t3206-range-diff.sh b/t/t3206-range-diff.sh
> index ec548654ce..5b87fead2e 100755
> --- a/t/t3206-range-diff.sh
> +++ b/t/t3206-range-diff.sh
> @@ -226,6 +226,46 @@ test_expect_success 'renamed file' '
> test_cmp expected actual
> '
>
> +test_expect_success 'file with mode only change' '
> + git range-diff --no-color --submodule=log topic...mode-only-change >actual &&
> + sed s/Z/\ /g >expected <<-EOF &&
> + 1: fccce22 ! 1: 4d39cb3 s/4/A/
> + @@ Metadata
> + ZAuthor: Thomas Rast <trast@xxxxxxxxxxx>
> + Z
> + Z ## Commit message ##
> + - s/4/A/
> + + s/4/A/ + add other-file
> + Z
> + Z ## file ##
> + Z@@
> + @@ file
> + Z A
> + Z 6
> + Z 7
> + +
> + + ## other-file (new) ##
> + 2: 147e64e ! 2: 26c107f s/11/B/
> + @@ Metadata
> + ZAuthor: Thomas Rast <trast@xxxxxxxxxxx>
> + Z
> + Z ## Commit message ##
> + - s/11/B/
> + + s/11/B/ + mode change other-file
> + Z
> + Z ## file ##
> + Z@@ file: A
> + @@ file: A
> + Z 12
> + Z 13
> + Z 14
> + +
> + + ## other-file (mode change 100644 => 100755) ##
> + 3: a63e992 = 3: 4c1e0f5 s/12/B/
> + EOF
> + test_cmp expected actual
> +'
> +
> test_expect_success 'file added and later removed' '
> git range-diff --no-color --submodule=log topic...added-removed >actual &&
> sed s/Z/\ /g >expected <<-EOF &&
> diff --git a/t/t3206/history.export b/t/t3206/history.export
> index 7bb3814962..4c808e5b3b 100644
> --- a/t/t3206/history.export
> +++ b/t/t3206/history.export
> @@ -55,7 +55,7 @@ A
> 19
> 20
>
> -commit refs/heads/topic
> +commit refs/heads/mode-only-change
> mark :4
> author Thomas Rast <trast@xxxxxxxxxxx> 1374485014 +0200
> committer Thomas Rast <trast@xxxxxxxxxxx> 1374485014 +0200
> @@ -678,3 +678,32 @@ s/12/B/
> from :55
> M 100644 :9 renamed-file
>
> +commit refs/heads/mode-only-change
> +mark :57
> +author Thomas Rast <trast@xxxxxxxxxxx> 1374485024 +0200
> +committer Thomas Gummerer <t.gummerer@xxxxxxxxx> 1570473767 +0100
> +data 24
> +s/4/A/ + add other-file
> +from :4
> +M 100644 :5 file
> +M 100644 :49 other-file
> +
> +commit refs/heads/mode-only-change
> +mark :58
> +author Thomas Rast <trast@xxxxxxxxxxx> 1374485036 +0200
> +committer Thomas Gummerer <t.gummerer@xxxxxxxxx> 1570473768 +0100
> +data 33
> +s/11/B/ + mode change other-file
> +from :57
> +M 100644 :7 file
> +M 100755 :49 other-file
> +
> +commit refs/heads/mode-only-change
> +mark :59
> +author Thomas Rast <trast@xxxxxxxxxxx> 1374485044 +0200
> +committer Thomas Gummerer <t.gummerer@xxxxxxxxx> 1570473768 +0100
> +data 8
> +s/12/B/
> +from :58
> +M 100644 :9 file
> +
> --
> 2.23.0.501.gb744c3af07
>
>
