git/utf8.c
Torsten Bögershausen 76759c7dff git on Mac OS and precomposed unicode
Mac OS X mangles file names containing unicode on file systems HFS+,
VFAT or SAMBA.  When a file using unicode code points outside ASCII
is created on a HFS+ drive, the file name is converted into
decomposed unicode and written to disk. No conversion is done if
the file name is already decomposed unicode.

Calling open("\xc3\x84", ...) with a precomposed "Ä" yields the same
result as open("\x41\xcc\x88",...) with a decomposed "Ä".

As a consequence, readdir() returns the file names in decomposed
unicode, even if the user expects precomposed unicode.  Unlike on
HFS+, Mac OS X stores files on a VFAT drive (e.g. an USB drive) in
precomposed unicode, but readdir() still returns file names in
decomposed unicode.  When a git repository is stored on a network
share using SAMBA, file names are send over the wire and written to
disk on the remote system in precomposed unicode, but Mac OS X
readdir() returns decomposed unicode to be compatible with its
behaviour on HFS+ and VFAT.

The unicode decomposition causes many problems:

- The names "git add" and other commands get from the end user may
  often be precomposed form (the decomposed form is not easily input
  from the keyboard), but when the commands read from the filesystem
  to see what it is going to update the index with already is on the
  filesystem, readdir() will give decomposed form, which is different.

- Similarly "git log", "git mv" and all other commands that need to
  compare pathnames found on the command line (often but not always
  precomposed form; a command line input resulting from globbing may
  be in decomposed) with pathnames found in the tree objects (should
  be precomposed form to be compatible with other systems and for
  consistency in general).

- The same for names stored in the index, which should be
  precomposed, that may need to be compared with the names read from
  readdir().

NFS mounted from Linux is fully transparent and does not suffer from
the above.

As Mac OS X treats precomposed and decomposed file names as equal,
we can

 - wrap readdir() on Mac OS X to return the precomposed form, and

 - normalize decomposed form given from the command line also to the
   precomposed form,

to ensure that all pathnames used in Git are always in the
precomposed form.  This behaviour can be requested by setting
"core.precomposedunicode" configuration variable to true.

The code in compat/precomposed_utf8.c implements basically 4 new
functions: precomposed_utf8_opendir(), precomposed_utf8_readdir(),
precomposed_utf8_closedir() and precompose_argv().  The first three
are to wrap opendir(3), readdir(3), and closedir(3) functions.

The argv[] conversion allows to use the TAB filename completion done
by the shell on command line.  It tolerates other tools which use
readdir() to feed decomposed file names into git.

When creating a new git repository with "git init" or "git clone",
"core.precomposedunicode" will be set "false".

The user needs to activate this feature manually.  She typically
sets core.precomposedunicode to "true" on HFS and VFAT, or file
systems mounted via SAMBA.

Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Torsten Bögershausen <tboegi@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-07-08 22:03:46 -07:00

491 lines
13 KiB
C

#include "git-compat-util.h"
#include "strbuf.h"
#include "utf8.h"
/* This code is originally from http://www.cl.cam.ac.uk/~mgk25/ucs/ */
struct interval {
int first;
int last;
};
/* auxiliary function for binary search in interval table */
static int bisearch(ucs_char_t ucs, const struct interval *table, int max)
{
int min = 0;
int mid;
if (ucs < table[0].first || ucs > table[max].last)
return 0;
while (max >= min) {
mid = (min + max) / 2;
if (ucs > table[mid].last)
min = mid + 1;
else if (ucs < table[mid].first)
max = mid - 1;
else
return 1;
}
return 0;
}
/* The following two functions define the column width of an ISO 10646
* character as follows:
*
* - The null character (U+0000) has a column width of 0.
*
* - Other C0/C1 control characters and DEL will lead to a return
* value of -1.
*
* - Non-spacing and enclosing combining characters (general
* category code Mn or Me in the Unicode database) have a
* column width of 0.
*
* - SOFT HYPHEN (U+00AD) has a column width of 1.
*
* - Other format characters (general category code Cf in the Unicode
* database) and ZERO WIDTH SPACE (U+200B) have a column width of 0.
*
* - Hangul Jamo medial vowels and final consonants (U+1160-U+11FF)
* have a column width of 0.
*
* - Spacing characters in the East Asian Wide (W) or East Asian
* Full-width (F) category as defined in Unicode Technical
* Report #11 have a column width of 2.
*
* - All remaining characters (including all printable
* ISO 8859-1 and WGL4 characters, Unicode control characters,
* etc.) have a column width of 1.
*
* This implementation assumes that ucs_char_t characters are encoded
* in ISO 10646.
*/
static int git_wcwidth(ucs_char_t ch)
{
/*
* Sorted list of non-overlapping intervals of non-spacing characters,
* generated by
* "uniset +cat=Me +cat=Mn +cat=Cf -00AD +1160-11FF +200B c".
*/
static const struct interval combining[] = {
{ 0x0300, 0x0357 }, { 0x035D, 0x036F }, { 0x0483, 0x0486 },
{ 0x0488, 0x0489 }, { 0x0591, 0x05A1 }, { 0x05A3, 0x05B9 },
{ 0x05BB, 0x05BD }, { 0x05BF, 0x05BF }, { 0x05C1, 0x05C2 },
{ 0x05C4, 0x05C4 }, { 0x0600, 0x0603 }, { 0x0610, 0x0615 },
{ 0x064B, 0x0658 }, { 0x0670, 0x0670 }, { 0x06D6, 0x06E4 },
{ 0x06E7, 0x06E8 }, { 0x06EA, 0x06ED }, { 0x070F, 0x070F },
{ 0x0711, 0x0711 }, { 0x0730, 0x074A }, { 0x07A6, 0x07B0 },
{ 0x0901, 0x0902 }, { 0x093C, 0x093C }, { 0x0941, 0x0948 },
{ 0x094D, 0x094D }, { 0x0951, 0x0954 }, { 0x0962, 0x0963 },
{ 0x0981, 0x0981 }, { 0x09BC, 0x09BC }, { 0x09C1, 0x09C4 },
{ 0x09CD, 0x09CD }, { 0x09E2, 0x09E3 }, { 0x0A01, 0x0A02 },
{ 0x0A3C, 0x0A3C }, { 0x0A41, 0x0A42 }, { 0x0A47, 0x0A48 },
{ 0x0A4B, 0x0A4D }, { 0x0A70, 0x0A71 }, { 0x0A81, 0x0A82 },
{ 0x0ABC, 0x0ABC }, { 0x0AC1, 0x0AC5 }, { 0x0AC7, 0x0AC8 },
{ 0x0ACD, 0x0ACD }, { 0x0AE2, 0x0AE3 }, { 0x0B01, 0x0B01 },
{ 0x0B3C, 0x0B3C }, { 0x0B3F, 0x0B3F }, { 0x0B41, 0x0B43 },
{ 0x0B4D, 0x0B4D }, { 0x0B56, 0x0B56 }, { 0x0B82, 0x0B82 },
{ 0x0BC0, 0x0BC0 }, { 0x0BCD, 0x0BCD }, { 0x0C3E, 0x0C40 },
{ 0x0C46, 0x0C48 }, { 0x0C4A, 0x0C4D }, { 0x0C55, 0x0C56 },
{ 0x0CBC, 0x0CBC }, { 0x0CBF, 0x0CBF }, { 0x0CC6, 0x0CC6 },
{ 0x0CCC, 0x0CCD }, { 0x0D41, 0x0D43 }, { 0x0D4D, 0x0D4D },
{ 0x0DCA, 0x0DCA }, { 0x0DD2, 0x0DD4 }, { 0x0DD6, 0x0DD6 },
{ 0x0E31, 0x0E31 }, { 0x0E34, 0x0E3A }, { 0x0E47, 0x0E4E },
{ 0x0EB1, 0x0EB1 }, { 0x0EB4, 0x0EB9 }, { 0x0EBB, 0x0EBC },
{ 0x0EC8, 0x0ECD }, { 0x0F18, 0x0F19 }, { 0x0F35, 0x0F35 },
{ 0x0F37, 0x0F37 }, { 0x0F39, 0x0F39 }, { 0x0F71, 0x0F7E },
{ 0x0F80, 0x0F84 }, { 0x0F86, 0x0F87 }, { 0x0F90, 0x0F97 },
{ 0x0F99, 0x0FBC }, { 0x0FC6, 0x0FC6 }, { 0x102D, 0x1030 },
{ 0x1032, 0x1032 }, { 0x1036, 0x1037 }, { 0x1039, 0x1039 },
{ 0x1058, 0x1059 }, { 0x1160, 0x11FF }, { 0x1712, 0x1714 },
{ 0x1732, 0x1734 }, { 0x1752, 0x1753 }, { 0x1772, 0x1773 },
{ 0x17B4, 0x17B5 }, { 0x17B7, 0x17BD }, { 0x17C6, 0x17C6 },
{ 0x17C9, 0x17D3 }, { 0x17DD, 0x17DD }, { 0x180B, 0x180D },
{ 0x18A9, 0x18A9 }, { 0x1920, 0x1922 }, { 0x1927, 0x1928 },
{ 0x1932, 0x1932 }, { 0x1939, 0x193B }, { 0x200B, 0x200F },
{ 0x202A, 0x202E }, { 0x2060, 0x2063 }, { 0x206A, 0x206F },
{ 0x20D0, 0x20EA }, { 0x302A, 0x302F }, { 0x3099, 0x309A },
{ 0xFB1E, 0xFB1E }, { 0xFE00, 0xFE0F }, { 0xFE20, 0xFE23 },
{ 0xFEFF, 0xFEFF }, { 0xFFF9, 0xFFFB }, { 0x1D167, 0x1D169 },
{ 0x1D173, 0x1D182 }, { 0x1D185, 0x1D18B },
{ 0x1D1AA, 0x1D1AD }, { 0xE0001, 0xE0001 },
{ 0xE0020, 0xE007F }, { 0xE0100, 0xE01EF }
};
/* test for 8-bit control characters */
if (ch == 0)
return 0;
if (ch < 32 || (ch >= 0x7f && ch < 0xa0))
return -1;
/* binary search in table of non-spacing characters */
if (bisearch(ch, combining, sizeof(combining)
/ sizeof(struct interval) - 1))
return 0;
/*
* If we arrive here, ch is neither a combining nor a C0/C1
* control character.
*/
return 1 +
(ch >= 0x1100 &&
/* Hangul Jamo init. consonants */
(ch <= 0x115f ||
ch == 0x2329 || ch == 0x232a ||
/* CJK ... Yi */
(ch >= 0x2e80 && ch <= 0xa4cf &&
ch != 0x303f) ||
/* Hangul Syllables */
(ch >= 0xac00 && ch <= 0xd7a3) ||
/* CJK Compatibility Ideographs */
(ch >= 0xf900 && ch <= 0xfaff) ||
/* CJK Compatibility Forms */
(ch >= 0xfe30 && ch <= 0xfe6f) ||
/* Fullwidth Forms */
(ch >= 0xff00 && ch <= 0xff60) ||
(ch >= 0xffe0 && ch <= 0xffe6) ||
(ch >= 0x20000 && ch <= 0x2fffd) ||
(ch >= 0x30000 && ch <= 0x3fffd)));
}
/*
* Pick one ucs character starting from the location *start points at,
* and return it, while updating the *start pointer to point at the
* end of that character. When remainder_p is not NULL, the location
* holds the number of bytes remaining in the string that we are allowed
* to pick from. Otherwise we are allowed to pick up to the NUL that
* would eventually appear in the string. *remainder_p is also reduced
* by the number of bytes we have consumed.
*
* If the string was not a valid UTF-8, *start pointer is set to NULL
* and the return value is undefined.
*/
static ucs_char_t pick_one_utf8_char(const char **start, size_t *remainder_p)
{
unsigned char *s = (unsigned char *)*start;
ucs_char_t ch;
size_t remainder, incr;
/*
* A caller that assumes NUL terminated text can choose
* not to bother with the remainder length. We will
* stop at the first NUL.
*/
remainder = (remainder_p ? *remainder_p : 999);
if (remainder < 1) {
goto invalid;
} else if (*s < 0x80) {
/* 0xxxxxxx */
ch = *s;
incr = 1;
} else if ((s[0] & 0xe0) == 0xc0) {
/* 110XXXXx 10xxxxxx */
if (remainder < 2 ||
(s[1] & 0xc0) != 0x80 ||
(s[0] & 0xfe) == 0xc0)
goto invalid;
ch = ((s[0] & 0x1f) << 6) | (s[1] & 0x3f);
incr = 2;
} else if ((s[0] & 0xf0) == 0xe0) {
/* 1110XXXX 10Xxxxxx 10xxxxxx */
if (remainder < 3 ||
(s[1] & 0xc0) != 0x80 ||
(s[2] & 0xc0) != 0x80 ||
/* overlong? */
(s[0] == 0xe0 && (s[1] & 0xe0) == 0x80) ||
/* surrogate? */
(s[0] == 0xed && (s[1] & 0xe0) == 0xa0) ||
/* U+FFFE or U+FFFF? */
(s[0] == 0xef && s[1] == 0xbf &&
(s[2] & 0xfe) == 0xbe))
goto invalid;
ch = ((s[0] & 0x0f) << 12) |
((s[1] & 0x3f) << 6) | (s[2] & 0x3f);
incr = 3;
} else if ((s[0] & 0xf8) == 0xf0) {
/* 11110XXX 10XXxxxx 10xxxxxx 10xxxxxx */
if (remainder < 4 ||
(s[1] & 0xc0) != 0x80 ||
(s[2] & 0xc0) != 0x80 ||
(s[3] & 0xc0) != 0x80 ||
/* overlong? */
(s[0] == 0xf0 && (s[1] & 0xf0) == 0x80) ||
/* > U+10FFFF? */
(s[0] == 0xf4 && s[1] > 0x8f) || s[0] > 0xf4)
goto invalid;
ch = ((s[0] & 0x07) << 18) | ((s[1] & 0x3f) << 12) |
((s[2] & 0x3f) << 6) | (s[3] & 0x3f);
incr = 4;
} else {
invalid:
*start = NULL;
return 0;
}
*start += incr;
if (remainder_p)
*remainder_p = remainder - incr;
return ch;
}
/*
* This function returns the number of columns occupied by the character
* pointed to by the variable start. The pointer is updated to point at
* the next character. When remainder_p is not NULL, it points at the
* location that stores the number of remaining bytes we can use to pick
* a character (see pick_one_utf8_char() above).
*/
int utf8_width(const char **start, size_t *remainder_p)
{
ucs_char_t ch = pick_one_utf8_char(start, remainder_p);
if (!*start)
return 0;
return git_wcwidth(ch);
}
/*
* Returns the total number of columns required by a null-terminated
* string, assuming that the string is utf8. Returns strlen() instead
* if the string does not look like a valid utf8 string.
*/
int utf8_strwidth(const char *string)
{
int width = 0;
const char *orig = string;
while (1) {
if (!string)
return strlen(orig);
if (!*string)
return width;
width += utf8_width(&string, NULL);
}
}
int is_utf8(const char *text)
{
while (*text) {
if (*text == '\n' || *text == '\t' || *text == '\r') {
text++;
continue;
}
utf8_width(&text, NULL);
if (!text)
return 0;
}
return 1;
}
static void strbuf_addchars(struct strbuf *sb, int c, size_t n)
{
strbuf_grow(sb, n);
memset(sb->buf + sb->len, c, n);
strbuf_setlen(sb, sb->len + n);
}
static void strbuf_add_indented_text(struct strbuf *buf, const char *text,
int indent, int indent2)
{
if (indent < 0)
indent = 0;
while (*text) {
const char *eol = strchrnul(text, '\n');
if (*eol == '\n')
eol++;
strbuf_addchars(buf, ' ', indent);
strbuf_add(buf, text, eol - text);
text = eol;
indent = indent2;
}
}
static size_t display_mode_esc_sequence_len(const char *s)
{
const char *p = s;
if (*p++ != '\033')
return 0;
if (*p++ != '[')
return 0;
while (isdigit(*p) || *p == ';')
p++;
if (*p++ != 'm')
return 0;
return p - s;
}
/*
* Wrap the text, if necessary. The variable indent is the indent for the
* first line, indent2 is the indent for all other lines.
* If indent is negative, assume that already -indent columns have been
* consumed (and no extra indent is necessary for the first line).
*/
int strbuf_add_wrapped_text(struct strbuf *buf,
const char *text, int indent1, int indent2, int width)
{
int indent, w, assume_utf8 = 1;
const char *bol, *space, *start = text;
size_t orig_len = buf->len;
if (width <= 0) {
strbuf_add_indented_text(buf, text, indent1, indent2);
return 1;
}
retry:
bol = text;
w = indent = indent1;
space = NULL;
if (indent < 0) {
w = -indent;
space = text;
}
for (;;) {
char c;
size_t skip;
while ((skip = display_mode_esc_sequence_len(text)))
text += skip;
c = *text;
if (!c || isspace(c)) {
if (w < width || !space) {
const char *start = bol;
if (!c && text == start)
return w;
if (space)
start = space;
else
strbuf_addchars(buf, ' ', indent);
strbuf_add(buf, start, text - start);
if (!c)
return w;
space = text;
if (c == '\t')
w |= 0x07;
else if (c == '\n') {
space++;
if (*space == '\n') {
strbuf_addch(buf, '\n');
goto new_line;
}
else if (!isalnum(*space))
goto new_line;
else
strbuf_addch(buf, ' ');
}
w++;
text++;
}
else {
new_line:
strbuf_addch(buf, '\n');
text = bol = space + isspace(*space);
space = NULL;
w = indent = indent2;
}
continue;
}
if (assume_utf8) {
w += utf8_width(&text, NULL);
if (!text) {
assume_utf8 = 0;
text = start;
strbuf_setlen(buf, orig_len);
goto retry;
}
} else {
w++;
text++;
}
}
}
int strbuf_add_wrapped_bytes(struct strbuf *buf, const char *data, int len,
int indent, int indent2, int width)
{
char *tmp = xstrndup(data, len);
int r = strbuf_add_wrapped_text(buf, tmp, indent, indent2, width);
free(tmp);
return r;
}
int is_encoding_utf8(const char *name)
{
if (!name)
return 1;
if (!strcasecmp(name, "utf-8") || !strcasecmp(name, "utf8"))
return 1;
return 0;
}
/*
* Given a buffer and its encoding, return it re-encoded
* with iconv. If the conversion fails, returns NULL.
*/
#ifndef NO_ICONV
#if defined(OLD_ICONV) || (defined(__sun__) && !defined(_XPG6))
typedef const char * iconv_ibp;
#else
typedef char * iconv_ibp;
#endif
char *reencode_string_iconv(const char *in, size_t insz, iconv_t conv)
{
size_t outsz, outalloc;
char *out, *outpos;
iconv_ibp cp;
outsz = insz;
outalloc = outsz + 1; /* for terminating NUL */
out = xmalloc(outalloc);
outpos = out;
cp = (iconv_ibp)in;
while (1) {
size_t cnt = iconv(conv, &cp, &insz, &outpos, &outsz);
if (cnt == -1) {
size_t sofar;
if (errno != E2BIG) {
free(out);
return NULL;
}
/* insz has remaining number of bytes.
* since we started outsz the same as insz,
* it is likely that insz is not enough for
* converting the rest.
*/
sofar = outpos - out;
outalloc = sofar + insz * 2 + 32;
out = xrealloc(out, outalloc);
outpos = out + sofar;
outsz = outalloc - sofar - 1;
}
else {
*outpos = '\0';
break;
}
}
return out;
}
char *reencode_string(const char *in, const char *out_encoding, const char *in_encoding)
{
iconv_t conv;
char *out;
if (!in_encoding)
return NULL;
conv = iconv_open(out_encoding, in_encoding);
if (conv == (iconv_t) -1)
return NULL;
out = reencode_string_iconv(in, strlen(in), conv);
iconv_close(conv);
return out;
}
#endif