> On 25 Feb 2018, at 20:50, Eric Sunshine <[email protected]> wrote:
>
> On Sat, Feb 24, 2018 at 11:28 AM, <[email protected]> wrote:
>> UTF supports lossless conversion round tripping and conversions between
>> UTF and other encodings are mostly round trip safe as Unicode aims to be
>> a superset of all other character encodings. However, certain encodings
>> (e.g. SHIFT-JIS) are known to have round trip issues [1].
>>
>> Add 'core.checkRoundtripEncoding', which contains a comma separated
>> list of encodings, to define for what encodings Git should check the
>> conversion round trip if they are used in the 'working-tree-encoding'
>> attribute.
>>
>> Set SHIFT-JIS as default value for 'core.checkRoundtripEncoding'.
>>
>> [1]
>> https://support.microsoft.com/en-us/help/170559/prb-conversion-problem-between-shift-jis-and-unicode
>>
>> Signed-off-by: Lars Schneider <[email protected]>
>> ---
>> diff --git a/convert.c b/convert.c
>> @@ -289,6 +289,39 @@ static void trace_encoding(const char *context, const
>> char *path,
>> +static int check_roundtrip(const char* enc_name)
>> +{
>> + /*
>> + * check_roundtrip_encoding contains a string of space and/or
>> + * comma separated encodings (eg. "UTF-16, ASCII, CP1125").
>> + * Search for the given encoding in that string.
>> + */
>> + const char *found = strcasestr(check_roundtrip_encoding, enc_name);
>> + const char *next = found + strlen(enc_name);
>
> Is this pointer arithmetic undefined behavior (according to the C
> standard) if NULL is returned by strcasestr()? If so, how comfortable
> are we with this? Perhaps if you add an 'if' into the mix, you can
> avoid it:
>
> if (found) {
> const char *next = found + strlen(enc_name);
> return ...long complicated expression...;
> }
> return false;
OK. I've fixed it this way:
if (!found)
return 0;
[...]
>> +
>> + if (!re_src || src_len != re_src_len ||
>> + memcmp(src, re_src, src_len)) {
>> + const char* msg = _("encoding '%s' from %s to %s and
>> "
>> + "back is not the same");
>> + die(msg, path, enc->name, default_encoding);
>
> Last two arguments need to be swapped.
Hm. Are you sure? I think it is correct as it is. We are in encode_to_git()
here and that means we encode *to* "default encoding", no?
>> + }
>> +
>> + free(re_src);
>> + }
>> +
>> strbuf_attach(buf, dst, dst_len, dst_len + 1);
>> return 1;
>> }
>> diff --git a/t/t0028-working-tree-encoding.sh
>> b/t/t0028-working-tree-encoding.sh
>> @@ -225,4 +225,45 @@ test_expect_success 'error if encoding garbage is
>> already in Git' '
>> +test_expect_success 'check roundtrip encoding' '
>> + text="hallo there!\nroundtrip test here!" &&
>> + printf "$text" | iconv -f UTF-8 -t SHIFT-JIS >roundtrip.shift &&
>> + printf "$text" | iconv -f UTF-8 -t UTF-16 >roundtrip.utf16 &&
>> + echo "*.shift text working-tree-encoding=SHIFT-JIS" >>.gitattributes
>> &&
>> +
>> + # SHIFT-JIS encoded files are round-trip checked by default...
>> + GIT_TRACE=1 git add .gitattributes roundtrip.shift 2>&1 >/dev/null |
>> + grep "Checking roundtrip encoding for SHIFT-JIS" &&
>
> Why redirect to /dev/null? If something does go wrong somewhere, the
> more output available for debugging the problem, the better, so
> throwing it away unnecessarily seems contraindicated.
OK!
>> + git reset &&
>> +
>> + # ... unless we overwrite the Git config!
>> + test_config core.checkRoundtripEncoding "garbage" &&
>> + ! GIT_TRACE=1 git add .gitattributes roundtrip.shift 2>&1 >/dev/null
>> |
>> + grep "Checking roundtrip encoding for SHIFT-JIS" &&
>> + test_unconfig core.checkRoundtripEncoding &&
>
> The "unconfig" won't take place if the test fails. Instead of
> test_config/test_unconfig, you could use '-c' to set the config
> transiently for the git-add operation:
>
> ! GIT_TRACE=1 git -c core.checkRoundtripEncoding=garbage add ...
Agreed. Although test_config (in t/test-lib-functions.sh) automatically
unsets itself after the test is over.
>> + git reset &&
>> +
>> + # UTF-16 encoded files should not be round-trip checked by default...
>> + ! GIT_TRACE=1 git add roundtrip.utf16 2>&1 >/dev/null |
>> + grep "Checking roundtrip encoding for UTF-16" &&
>> + git reset &&
>> +
>> + # ... unless we tell Git to check it!
>> + test_config_global core.checkRoundtripEncoding "UTF-16, UTF-32" &&
>> + GIT_TRACE=1 git add roundtrip.utf16 2>&1 >/dev/null |
>> + grep "Checking roundtrip encoding for UTF-16" &&
>> + git reset &&
>> +
>> + # ... unless we tell Git to check it!
>> + # (here we also check that the casing of the encoding is irrelevant)
>> + test_config_global core.checkRoundtripEncoding "UTF-32, utf-16" &&
>> + GIT_TRACE=1 git add roundtrip.utf16 2>&1 >/dev/null |
>> + grep "Checking roundtrip encoding for UTF-16" &&
>> + git reset &&
>> +
>> + # cleanup
>> + rm roundtrip.shift roundtrip.utf16 &&
>> + git reset --hard HEAD
>> +'
>
> Same comment as for patch 5/7: This cleanup won't happen if the test
> fails. Instead, use test_when_finished() earlier in the test:
>
> test_expect_success 'check roundtrip encoding' '
> test_when_finished "rm -f roundtrip.shift roundtrip.utf16; git
> reset --hard HEAD" &&
> ...
Agreed!
Thanks you,
Lars
