git/convert.c
Andy Parkins 760f0c62ef Fix crlf attribute handling to match documentation
gitattributes.txt says, of the crlf attribute:

 Set::
    Setting the `crlf` attribute on a path is meant to mark
    the path as a "text" file.  'core.autocrlf' conversion
    takes place without guessing the content type by
    inspection.

That is to say that the crlf attribute does not force the file to have
CRLF line endings, instead it removes the autocrlf guesswork and forces
the file to be treated as text.  Then, whatever line ending is defined
by the autocrlf setting is applied.

However, that is not what convert.c was doing.  The conversion to CRLF
was being skipped in crlf_to_worktree() when the following condition was
true:

 action == CRLF_GUESS && auto_crlf <= 0

That is to say conversion took place when not in guess mode (crlf attribute
not specified) or core.autocrlf set to true.  This was wrong.  It meant
that the crlf attribute being on for a given file _forced_ CRLF
conversion, when actually it should force the file to be treated as
text, and converted accordingly.  The real test should simply be

 auto_crlf <= 0

That is to say, if core.autocrlf is falsei (or input), conversion from
LF to CRLF is never done.  When core.autocrlf is true, conversion from
LF to CRLF is done only when in CRLF_GUESS (and the guess is "text"), or
CRLF_TEXT mode.

Similarly for crlf_to_worktree(), if core.autocrlf is false, no conversion
should _ever_ take place.  In reality it was only not taking place if
core.autocrlf was false _and_ the crlf attribute was unspecified.

Signed-off-by: Andy Parkins <andyparkins@gmail.com>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-05-18 17:02:47 -07:00

670 lines
14 KiB
C

#include "cache.h"
#include "attr.h"
#include "run-command.h"
/*
* convert.c - convert a file when checking it out and checking it in.
*
* This should use the pathname to decide on whether it wants to do some
* more interesting conversions (automatic gzip/unzip, general format
* conversions etc etc), but by default it just does automatic CRLF<->LF
* translation when the "auto_crlf" option is set.
*/
#define CRLF_GUESS (-1)
#define CRLF_BINARY 0
#define CRLF_TEXT 1
#define CRLF_INPUT 2
struct text_stat {
/* CR, LF and CRLF counts */
unsigned cr, lf, crlf;
/* These are just approximations! */
unsigned printable, nonprintable;
};
static void gather_stats(const char *buf, unsigned long size, struct text_stat *stats)
{
unsigned long i;
memset(stats, 0, sizeof(*stats));
for (i = 0; i < size; i++) {
unsigned char c = buf[i];
if (c == '\r') {
stats->cr++;
if (i+1 < size && buf[i+1] == '\n')
stats->crlf++;
continue;
}
if (c == '\n') {
stats->lf++;
continue;
}
if (c == 127)
/* DEL */
stats->nonprintable++;
else if (c < 32) {
switch (c) {
/* BS, HT, ESC and FF */
case '\b': case '\t': case '\033': case '\014':
stats->printable++;
break;
default:
stats->nonprintable++;
}
}
else
stats->printable++;
}
}
/*
* The same heuristics as diff.c::mmfile_is_binary()
*/
static int is_binary(unsigned long size, struct text_stat *stats)
{
if ((stats->printable >> 7) < stats->nonprintable)
return 1;
/*
* Other heuristics? Average line length might be relevant,
* as might LF vs CR vs CRLF counts..
*
* NOTE! It might be normal to have a low ratio of CRLF to LF
* (somebody starts with a LF-only file and edits it with an editor
* that adds CRLF only to lines that are added..). But do we
* want to support CR-only? Probably not.
*/
return 0;
}
static char *crlf_to_git(const char *path, const char *src, unsigned long *sizep, int action)
{
char *buffer, *dst;
unsigned long size, nsize;
struct text_stat stats;
if ((action == CRLF_BINARY) || !auto_crlf)
return NULL;
size = *sizep;
if (!size)
return NULL;
gather_stats(src, size, &stats);
/* No CR? Nothing to convert, regardless. */
if (!stats.cr)
return NULL;
if (action == CRLF_GUESS) {
/*
* We're currently not going to even try to convert stuff
* that has bare CR characters. Does anybody do that crazy
* stuff?
*/
if (stats.cr != stats.crlf)
return NULL;
/*
* And add some heuristics for binary vs text, of course...
*/
if (is_binary(size, &stats))
return NULL;
}
/*
* Ok, allocate a new buffer, fill it in, and return it
* to let the caller know that we switched buffers.
*/
nsize = size - stats.crlf;
buffer = xmalloc(nsize);
*sizep = nsize;
dst = buffer;
if (action == CRLF_GUESS) {
/*
* If we guessed, we already know we rejected a file with
* lone CR, and we can strip a CR without looking at what
* follow it.
*/
do {
unsigned char c = *src++;
if (c != '\r')
*dst++ = c;
} while (--size);
} else {
do {
unsigned char c = *src++;
if (! (c == '\r' && (1 < size && *src == '\n')))
*dst++ = c;
} while (--size);
}
return buffer;
}
static char *crlf_to_worktree(const char *path, const char *src, unsigned long *sizep, int action)
{
char *buffer, *dst;
unsigned long size, nsize;
struct text_stat stats;
unsigned char last;
if ((action == CRLF_BINARY) || (action == CRLF_INPUT) ||
auto_crlf <= 0)
return NULL;
size = *sizep;
if (!size)
return NULL;
gather_stats(src, size, &stats);
/* No LF? Nothing to convert, regardless. */
if (!stats.lf)
return NULL;
/* Was it already in CRLF format? */
if (stats.lf == stats.crlf)
return NULL;
if (action == CRLF_GUESS) {
/* If we have any bare CR characters, we're not going to touch it */
if (stats.cr != stats.crlf)
return NULL;
if (is_binary(size, &stats))
return NULL;
}
/*
* Ok, allocate a new buffer, fill it in, and return it
* to let the caller know that we switched buffers.
*/
nsize = size + stats.lf - stats.crlf;
buffer = xmalloc(nsize);
*sizep = nsize;
last = 0;
dst = buffer;
do {
unsigned char c = *src++;
if (c == '\n' && last != '\r')
*dst++ = '\r';
*dst++ = c;
last = c;
} while (--size);
return buffer;
}
static int filter_buffer(const char *path, const char *src,
unsigned long size, const char *cmd)
{
/*
* Spawn cmd and feed the buffer contents through its stdin.
*/
struct child_process child_process;
int pipe_feed[2];
int write_err, status;
memset(&child_process, 0, sizeof(child_process));
if (pipe(pipe_feed) < 0) {
error("cannot create pipe to run external filter %s", cmd);
return 1;
}
child_process.pid = fork();
if (child_process.pid < 0) {
error("cannot fork to run external filter %s", cmd);
close(pipe_feed[0]);
close(pipe_feed[1]);
return 1;
}
if (!child_process.pid) {
dup2(pipe_feed[0], 0);
close(pipe_feed[0]);
close(pipe_feed[1]);
execlp("sh", "sh", "-c", cmd, NULL);
return 1;
}
close(pipe_feed[0]);
write_err = (write_in_full(pipe_feed[1], src, size) < 0);
if (close(pipe_feed[1]))
write_err = 1;
if (write_err)
error("cannot feed the input to external filter %s", cmd);
status = finish_command(&child_process);
if (status)
error("external filter %s failed %d", cmd, -status);
return (write_err || status);
}
static char *apply_filter(const char *path, const char *src,
unsigned long *sizep, const char *cmd)
{
/*
* Create a pipeline to have the command filter the buffer's
* contents.
*
* (child --> cmd) --> us
*/
const int SLOP = 4096;
int pipe_feed[2];
int status;
char *dst;
unsigned long dstsize, dstalloc;
struct child_process child_process;
if (!cmd)
return NULL;
memset(&child_process, 0, sizeof(child_process));
if (pipe(pipe_feed) < 0) {
error("cannot create pipe to run external filter %s", cmd);
return NULL;
}
fflush(NULL);
child_process.pid = fork();
if (child_process.pid < 0) {
error("cannot fork to run external filter %s", cmd);
close(pipe_feed[0]);
close(pipe_feed[1]);
return NULL;
}
if (!child_process.pid) {
dup2(pipe_feed[1], 1);
close(pipe_feed[0]);
close(pipe_feed[1]);
exit(filter_buffer(path, src, *sizep, cmd));
}
close(pipe_feed[1]);
dstalloc = *sizep;
dst = xmalloc(dstalloc);
dstsize = 0;
while (1) {
ssize_t numread = xread(pipe_feed[0], dst + dstsize,
dstalloc - dstsize);
if (numread <= 0) {
if (!numread)
break;
error("read from external filter %s failed", cmd);
free(dst);
dst = NULL;
break;
}
dstsize += numread;
if (dstalloc <= dstsize + SLOP) {
dstalloc = dstsize + SLOP;
dst = xrealloc(dst, dstalloc);
}
}
if (close(pipe_feed[0])) {
error("read from external filter %s failed", cmd);
free(dst);
dst = NULL;
}
status = finish_command(&child_process);
if (status) {
error("external filter %s failed %d", cmd, -status);
free(dst);
dst = NULL;
}
if (dst)
*sizep = dstsize;
return dst;
}
static struct convert_driver {
const char *name;
struct convert_driver *next;
char *smudge;
char *clean;
} *user_convert, **user_convert_tail;
static int read_convert_config(const char *var, const char *value)
{
const char *ep, *name;
int namelen;
struct convert_driver *drv;
/*
* External conversion drivers are configured using
* "filter.<name>.variable".
*/
if (prefixcmp(var, "filter.") || (ep = strrchr(var, '.')) == var + 6)
return 0;
name = var + 7;
namelen = ep - name;
for (drv = user_convert; drv; drv = drv->next)
if (!strncmp(drv->name, name, namelen) && !drv->name[namelen])
break;
if (!drv) {
char *namebuf;
drv = xcalloc(1, sizeof(struct convert_driver));
namebuf = xmalloc(namelen + 1);
memcpy(namebuf, name, namelen);
namebuf[namelen] = 0;
drv->name = namebuf;
drv->next = NULL;
*user_convert_tail = drv;
user_convert_tail = &(drv->next);
}
ep++;
/*
* filter.<name>.smudge and filter.<name>.clean specifies
* the command line:
*
* command-line
*
* The command-line will not be interpolated in any way.
*/
if (!strcmp("smudge", ep)) {
if (!value)
return error("%s: lacks value", var);
drv->smudge = strdup(value);
return 0;
}
if (!strcmp("clean", ep)) {
if (!value)
return error("%s: lacks value", var);
drv->clean = strdup(value);
return 0;
}
return 0;
}
static void setup_convert_check(struct git_attr_check *check)
{
static struct git_attr *attr_crlf;
static struct git_attr *attr_ident;
static struct git_attr *attr_filter;
if (!attr_crlf) {
attr_crlf = git_attr("crlf", 4);
attr_ident = git_attr("ident", 5);
attr_filter = git_attr("filter", 6);
user_convert_tail = &user_convert;
git_config(read_convert_config);
}
check[0].attr = attr_crlf;
check[1].attr = attr_ident;
check[2].attr = attr_filter;
}
static int count_ident(const char *cp, unsigned long size)
{
/*
* "$Id: 0000000000000000000000000000000000000000 $" <=> "$Id$"
*/
int cnt = 0;
char ch;
while (size) {
ch = *cp++;
size--;
if (ch != '$')
continue;
if (size < 3)
break;
if (memcmp("Id", cp, 2))
continue;
ch = cp[2];
cp += 3;
size -= 3;
if (ch == '$')
cnt++; /* $Id$ */
if (ch != ':')
continue;
/*
* "$Id: ... "; scan up to the closing dollar sign and discard.
*/
while (size) {
ch = *cp++;
size--;
if (ch == '$') {
cnt++;
break;
}
}
}
return cnt;
}
static char *ident_to_git(const char *path, const char *src, unsigned long *sizep, int ident)
{
int cnt;
unsigned long size;
char *dst, *buf;
if (!ident)
return NULL;
size = *sizep;
cnt = count_ident(src, size);
if (!cnt)
return NULL;
buf = xmalloc(size);
for (dst = buf; size; size--) {
char ch = *src++;
*dst++ = ch;
if ((ch == '$') && (3 <= size) &&
!memcmp("Id:", src, 3)) {
unsigned long rem = size - 3;
const char *cp = src + 3;
do {
ch = *cp++;
if (ch == '$')
break;
rem--;
} while (rem);
if (!rem)
continue;
memcpy(dst, "Id$", 3);
dst += 3;
size -= (cp - src);
src = cp;
}
}
*sizep = dst - buf;
return buf;
}
static char *ident_to_worktree(const char *path, const char *src, unsigned long *sizep, int ident)
{
int cnt;
unsigned long size;
char *dst, *buf;
unsigned char sha1[20];
if (!ident)
return NULL;
size = *sizep;
cnt = count_ident(src, size);
if (!cnt)
return NULL;
hash_sha1_file(src, size, "blob", sha1);
buf = xmalloc(size + cnt * 43);
for (dst = buf; size; size--) {
const char *cp;
char ch = *src++;
*dst++ = ch;
if ((ch != '$') || (size < 3) || memcmp("Id", src, 2))
continue;
if (src[2] == ':') {
/* discard up to but not including the closing $ */
unsigned long rem = size - 3;
cp = src + 3;
do {
ch = *cp++;
if (ch == '$')
break;
rem--;
} while (rem);
if (!rem)
continue;
size -= (cp - src);
} else if (src[2] == '$')
cp = src + 2;
else
continue;
memcpy(dst, "Id: ", 4);
dst += 4;
memcpy(dst, sha1_to_hex(sha1), 40);
dst += 40;
*dst++ = ' ';
size -= (cp - src);
src = cp;
*dst++ = *src++;
size--;
}
*sizep = dst - buf;
return buf;
}
static int git_path_check_crlf(const char *path, struct git_attr_check *check)
{
const char *value = check->value;
if (ATTR_TRUE(value))
return CRLF_TEXT;
else if (ATTR_FALSE(value))
return CRLF_BINARY;
else if (ATTR_UNSET(value))
;
else if (!strcmp(value, "input"))
return CRLF_INPUT;
return CRLF_GUESS;
}
static struct convert_driver *git_path_check_convert(const char *path,
struct git_attr_check *check)
{
const char *value = check->value;
struct convert_driver *drv;
if (ATTR_TRUE(value) || ATTR_FALSE(value) || ATTR_UNSET(value))
return NULL;
for (drv = user_convert; drv; drv = drv->next)
if (!strcmp(value, drv->name))
return drv;
return NULL;
}
static int git_path_check_ident(const char *path, struct git_attr_check *check)
{
const char *value = check->value;
return !!ATTR_TRUE(value);
}
char *convert_to_git(const char *path, const char *src, unsigned long *sizep)
{
struct git_attr_check check[3];
int crlf = CRLF_GUESS;
int ident = 0;
char *filter = NULL;
char *buf, *buf2;
setup_convert_check(check);
if (!git_checkattr(path, ARRAY_SIZE(check), check)) {
struct convert_driver *drv;
crlf = git_path_check_crlf(path, check + 0);
ident = git_path_check_ident(path, check + 1);
drv = git_path_check_convert(path, check + 2);
if (drv && drv->clean)
filter = drv->clean;
}
buf = apply_filter(path, src, sizep, filter);
buf2 = crlf_to_git(path, buf ? buf : src, sizep, crlf);
if (buf2) {
free(buf);
buf = buf2;
}
buf2 = ident_to_git(path, buf ? buf : src, sizep, ident);
if (buf2) {
free(buf);
buf = buf2;
}
return buf;
}
char *convert_to_working_tree(const char *path, const char *src, unsigned long *sizep)
{
struct git_attr_check check[3];
int crlf = CRLF_GUESS;
int ident = 0;
char *filter = NULL;
char *buf, *buf2;
setup_convert_check(check);
if (!git_checkattr(path, ARRAY_SIZE(check), check)) {
struct convert_driver *drv;
crlf = git_path_check_crlf(path, check + 0);
ident = git_path_check_ident(path, check + 1);
drv = git_path_check_convert(path, check + 2);
if (drv && drv->smudge)
filter = drv->smudge;
}
buf = ident_to_worktree(path, src, sizep, ident);
buf2 = crlf_to_worktree(path, buf ? buf : src, sizep, crlf);
if (buf2) {
free(buf);
buf = buf2;
}
buf2 = apply_filter(path, buf ? buf : src, sizep, filter);
if (buf2) {
free(buf);
buf = buf2;
}
return buf;
}
void *convert_sha1_file(const char *path, const unsigned char *sha1,
unsigned int mode, enum object_type *type,
unsigned long *size)
{
void *buffer = read_sha1_file(sha1, type, size);
if (S_ISREG(mode) && buffer) {
void *converted = convert_to_working_tree(path, buffer, size);
if (converted) {
free(buffer);
buffer = converted;
}
}
return buffer;
}