Re: [PATCH v5] wildmatch: properly fold case everywhere
Hello Junio,
Replied inline.
Regards,
--
Anthony Ramine
Le 2 juin 2013 à 23:53, Junio C Hamano a écrit :
> Anthony Ramine <n.oxyde@gmail.com> writes:
>
>> ase folding is not done correctly when matching against the [:upper:]
>> character class and uppercased character ranges (e.g. A-Z).
>> Specifically, an uppercase letter fails to match against any of them
>> when case folding is requested because plain characters in the pattern
>> and the whole string are preemptively lowercased to handle the base case
>> fast.
>>
>> That optimization is kept and ISLOWER() is used in the [:upper:] case
>> when case folding is requested, while matching against a character range
>> is retried with toupper() if the character was lowercase, as the bounds
>> of the range itself cannot be modified (in a case-insensitive context,
>> [A-_] is not equivalent to [a-_]).
>>
>> Signed-off-by: Anthony Ramine <n.oxyde@gmail.com>
>> Reviewed-by: Duy Nguyen <pclouds@gmail.com>
>> ---
>
> Thanks.
>
>> t/t3070-wildmatch.sh | 55 ++++++++++++++++++++++++++++++++++++++++++++++------
>> wildmatch.c | 7 +++++++
>> 2 files changed, 56 insertions(+), 6 deletions(-)
>>
>> I added Duy as reviewer and fixed a typo in the commit message reported by
>> Eric Sunshine.
>>
>> diff --git a/t/t3070-wildmatch.sh b/t/t3070-wildmatch.sh
>> index 4c37057..38446a0 100755
>> --- a/t/t3070-wildmatch.sh
>> +++ b/t/t3070-wildmatch.sh
>> @@ -6,20 +6,20 @@ test_description='wildmatch tests'
>>
>> match() {
>> if [ $1 = 1 ]; then
>> - test_expect_success "wildmatch: match '$3' '$4'" "
>> + test_expect_success "wildmatch: match '$3' '$4'" "
>> test-wildmatch wildmatch '$3' '$4'
>> "
>> else
>> - test_expect_success "wildmatch: no match '$3' '$4'" "
>> + test_expect_success "wildmatch: no match '$3' '$4'" "
>> ! test-wildmatch wildmatch '$3' '$4'
>> "
>> fi
>> if [ $2 = 1 ]; then
>> - test_expect_success "fnmatch: match '$3' '$4'" "
>> + test_expect_success "fnmatch: match '$3' '$4'" "
>> test-wildmatch fnmatch '$3' '$4'
>> "
>> elif [ $2 = 0 ]; then
>> - test_expect_success "fnmatch: no match '$3' '$4'" "
>> + test_expect_success "fnmatch: no match '$3' '$4'" "
>> ! test-wildmatch fnmatch '$3' '$4'
>> "
>> # else
>
> Is the above about aligning $3/$4 across checks of different types
> (i.e. purely cosmetic)? I am not complaining; just making sure if
> there is nothing deeper going on.
Yes purely cosmetic.
> It is outside the scope of this change, but the shell style of this
> script (most notably use of [] instead of test) needs to be fixed
> someday, preferrably soon, including the commented out else clause
> at the end of the hunk.
>
>> @@ -235,4 +247,35 @@ pathmatch 1 abcXdefXghi '*X*i'
>> pathmatch 1 ab/cXd/efXg/hi '*/*X*/*/*i'
>> pathmatch 1 ab/cXd/efXg/hi '*Xg*i'
>>
>> +# Case-sensitivy features
>> +match 0 x 'a' '[A-Z]'
>> +match 1 x 'A' '[A-Z]'
>> +match 0 x 'A' '[a-z]'
>> +match 1 x 'a' '[a-z]'
>> +match 0 x 'a' '[[:upper:]]'
>> +match 1 x 'A' '[[:upper:]]'
>> +match 0 x 'A' '[[:lower:]]'
>> +match 1 x 'a' '[[:lower:]]'
>> +match 0 x 'A' '[B-Za]'
>> +match 1 x 'a' '[B-Za]'
>> +match 0 x 'A' '[B-a]'
>> +match 1 x 'a' '[B-a]'
>> +match 0 x 'z' '[Z-y]'
>> +match 1 x 'Z' '[Z-y]'
>> +
>> +imatch 1 'a' '[A-Z]'
>
> Do we want "# Case-insensitivity features" commment here as well?
I don't particularly care, some sections have titles, some don't.
>> +imatch 1 'A' '[A-Z]'
>> +imatch 1 'A' '[a-z]'
>> +imatch 1 'a' '[a-z]'
>> +imatch 1 'a' '[[:upper:]]'
>> +imatch 1 'A' '[[:upper:]]'
>> +imatch 1 'A' '[[:lower:]]'
>> +imatch 1 'a' '[[:lower:]]'
>> +imatch 1 'A' '[B-Za]'
>> +imatch 1 'a' '[B-Za]'
>> +imatch 1 'A' '[B-a]'
>> +imatch 1 'a' '[B-a]'
>> +imatch 1 'z' '[Z-y]'
>> +imatch 1 'Z' '[Z-y]'
>
>> +
>> test_done
>> diff --git a/wildmatch.c b/wildmatch.c
>> index 7192bdc..f91ba99 100644
>> --- a/wildmatch.c
>> +++ b/wildmatch.c
>> @@ -196,6 +196,11 @@ static int dowild(const uchar *p, const uchar *text, unsigned int flags)
>> }
>> if (t_ch <= p_ch && t_ch >= prev_ch)
>> matched = 1;
>> + else if ((flags & WM_CASEFOLD) && ISLOWER(t_ch)) {
>> + uchar t_ch_upper = toupper(t_ch);
>> + if (t_ch_upper <= p_ch && t_ch_upper >= prev_ch)
>> + matched = 1;
>> + }
>> p_ch = 0; /* This makes "prev_ch" get set to 0. */
>
> Hmm, this looks somewhat strange.
>
> * At the beginning of the outermost "per characters in the text"
> loop, we seem to downcase t_ch when WM_CASEFOLD is set.
> * Also at the same place, we also seem to downcase p_ch under the
> same condition.
>
> which makes me wonder why the fix is not like this:
>
> + if (flags & WM_CASEFOLD) {
> + if (ISUPPER(p_ch))
> + p_ch = tolower(p_ch);
> + if (prev_ch && ISUPPER(prev_ch))
> + prev_ch = tolower(prev_ch);
> + }
> if (t_ch <= p_ch && t_ch >= prev_ch)
> matched = 1;
> p_ch = 0; /* This sets "prev_ch" to 0 */
>
>
> Ahh, OK, the "seemingly strange" construct is about handling a range
> like "[Z-y]"; we do not want to upcase or downcase the p_ch/prev_ch
> make the range "[z-y]" (empty) which would exclude bytes like "^",
> "_" or even "Z".
>
> And it is also OK to downcase p_ch in a single-letter case, not the
> characters in a range, at the beginning of the outermost loop,
> because we always compare for equality against t_ch (which is
> downcased) in that case.
Yeah I tried to explain that in the commit message but it is surely too dense.
>> @@ -245,6 +250,8 @@ static int dowild(const uchar *p, const uchar *text, unsigned int flags)
>> } else if (CC_EQ(s,i, "upper")) {
>> if (ISUPPER(t_ch))
>> matched = 1;
>> + else if ((flags & WM_CASEFOLD) && ISLOWER(t_ch))
>> + matched = 1;
>
> This also looks somewhat strange but correct in that t_ch is already
> downcased so we do not need a corresponding change for CC_EQ("lower")
> codepath.
I chose to still lowercase everything first, to keep the common path as is.
> Interesting. Will apply.
>
> Thanks.
Great. You're welcome.Anthony Ramine <n.oxyde@gmail.com>