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![Andy Parkins](/assets/img/avatar_default.png)
If the repository contained an expanded ident keyword (i.e. $Id:XXXX$), then the wrong bytes were discarded, and the Id keyword was not expanded. The fault was in convert.c:ident_to_worktree(). Previously, when a "$Id:" was found in the repository version, ident_to_worktree() would search for the next "$" after this, and discarded everything it found until then. That was done with the loop: do { ch = *cp++; if (ch == '$') break; rem--; } while (rem); The above loop left cp pointing one character _after_ the final "$" (because of ch = *cp++). This was different from the non-expanded case, were cp is left pointing at the "$", and was different from the comment which stated "discard up to but not including the closing $". This patch fixes that by making the loop: do { ch = *cp; if (ch == '$') break; cp++; rem--; } while (rem); That is, cp is tested _then_ incremented. This loop exits if it finds a "$" or if it runs out of bytes in the source. After this loop, if there was no closing "$" the expansion is skipped, and the outer loop is allowed to continue leaving this non-keyword as it was. However, when the "$" is found, size is corrected, before running the expansion: size -= (cp - src); This is wrong; size is going to be corrected anyway after the expansion, so there is no need to do it here. This patch removes that redundant correction. To help find this bug, I heavily commented the routine; those comments are included here as a bonus. Signed-off-by: Andy Parkins <andyparkins@gmail.com> Signed-off-by: Junio C Hamano <junkio@cox.net>
705 lines
15 KiB
C
705 lines
15 KiB
C
#include "cache.h"
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#include "attr.h"
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#include "run-command.h"
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/*
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* convert.c - convert a file when checking it out and checking it in.
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*
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* This should use the pathname to decide on whether it wants to do some
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* more interesting conversions (automatic gzip/unzip, general format
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* conversions etc etc), but by default it just does automatic CRLF<->LF
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* translation when the "auto_crlf" option is set.
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*/
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#define CRLF_GUESS (-1)
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#define CRLF_BINARY 0
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#define CRLF_TEXT 1
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#define CRLF_INPUT 2
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struct text_stat {
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/* CR, LF and CRLF counts */
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unsigned cr, lf, crlf;
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/* These are just approximations! */
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unsigned printable, nonprintable;
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};
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static void gather_stats(const char *buf, unsigned long size, struct text_stat *stats)
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{
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unsigned long i;
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memset(stats, 0, sizeof(*stats));
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for (i = 0; i < size; i++) {
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unsigned char c = buf[i];
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if (c == '\r') {
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stats->cr++;
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if (i+1 < size && buf[i+1] == '\n')
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stats->crlf++;
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continue;
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}
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if (c == '\n') {
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stats->lf++;
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continue;
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}
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if (c == 127)
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/* DEL */
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stats->nonprintable++;
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else if (c < 32) {
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switch (c) {
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/* BS, HT, ESC and FF */
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case '\b': case '\t': case '\033': case '\014':
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stats->printable++;
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break;
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default:
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stats->nonprintable++;
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}
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}
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else
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stats->printable++;
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}
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}
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/*
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* The same heuristics as diff.c::mmfile_is_binary()
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*/
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static int is_binary(unsigned long size, struct text_stat *stats)
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{
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if ((stats->printable >> 7) < stats->nonprintable)
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return 1;
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/*
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* Other heuristics? Average line length might be relevant,
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* as might LF vs CR vs CRLF counts..
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*
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* NOTE! It might be normal to have a low ratio of CRLF to LF
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* (somebody starts with a LF-only file and edits it with an editor
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* that adds CRLF only to lines that are added..). But do we
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* want to support CR-only? Probably not.
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*/
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return 0;
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}
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static char *crlf_to_git(const char *path, const char *src, unsigned long *sizep, int action)
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{
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char *buffer, *dst;
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unsigned long size, nsize;
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struct text_stat stats;
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if ((action == CRLF_BINARY) || !auto_crlf)
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return NULL;
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size = *sizep;
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if (!size)
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return NULL;
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gather_stats(src, size, &stats);
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/* No CR? Nothing to convert, regardless. */
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if (!stats.cr)
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return NULL;
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if (action == CRLF_GUESS) {
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/*
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* We're currently not going to even try to convert stuff
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* that has bare CR characters. Does anybody do that crazy
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* stuff?
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*/
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if (stats.cr != stats.crlf)
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return NULL;
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/*
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* And add some heuristics for binary vs text, of course...
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*/
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if (is_binary(size, &stats))
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return NULL;
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}
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/*
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* Ok, allocate a new buffer, fill it in, and return it
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* to let the caller know that we switched buffers.
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*/
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nsize = size - stats.crlf;
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buffer = xmalloc(nsize);
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*sizep = nsize;
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dst = buffer;
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if (action == CRLF_GUESS) {
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/*
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* If we guessed, we already know we rejected a file with
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* lone CR, and we can strip a CR without looking at what
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* follow it.
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*/
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do {
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unsigned char c = *src++;
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if (c != '\r')
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*dst++ = c;
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} while (--size);
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} else {
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do {
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unsigned char c = *src++;
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if (! (c == '\r' && (1 < size && *src == '\n')))
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*dst++ = c;
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} while (--size);
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}
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return buffer;
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}
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static char *crlf_to_worktree(const char *path, const char *src, unsigned long *sizep, int action)
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{
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char *buffer, *dst;
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unsigned long size, nsize;
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struct text_stat stats;
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unsigned char last;
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if ((action == CRLF_BINARY) || (action == CRLF_INPUT) ||
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auto_crlf <= 0)
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return NULL;
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size = *sizep;
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if (!size)
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return NULL;
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gather_stats(src, size, &stats);
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/* No LF? Nothing to convert, regardless. */
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if (!stats.lf)
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return NULL;
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/* Was it already in CRLF format? */
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if (stats.lf == stats.crlf)
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return NULL;
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if (action == CRLF_GUESS) {
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/* If we have any bare CR characters, we're not going to touch it */
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if (stats.cr != stats.crlf)
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return NULL;
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if (is_binary(size, &stats))
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return NULL;
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}
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/*
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* Ok, allocate a new buffer, fill it in, and return it
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* to let the caller know that we switched buffers.
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*/
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nsize = size + stats.lf - stats.crlf;
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buffer = xmalloc(nsize);
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*sizep = nsize;
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last = 0;
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dst = buffer;
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do {
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unsigned char c = *src++;
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if (c == '\n' && last != '\r')
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*dst++ = '\r';
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*dst++ = c;
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last = c;
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} while (--size);
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return buffer;
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}
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static int filter_buffer(const char *path, const char *src,
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unsigned long size, const char *cmd)
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{
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/*
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* Spawn cmd and feed the buffer contents through its stdin.
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*/
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struct child_process child_process;
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int pipe_feed[2];
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int write_err, status;
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memset(&child_process, 0, sizeof(child_process));
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if (pipe(pipe_feed) < 0) {
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error("cannot create pipe to run external filter %s", cmd);
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return 1;
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}
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child_process.pid = fork();
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if (child_process.pid < 0) {
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error("cannot fork to run external filter %s", cmd);
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close(pipe_feed[0]);
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close(pipe_feed[1]);
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return 1;
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}
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if (!child_process.pid) {
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dup2(pipe_feed[0], 0);
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close(pipe_feed[0]);
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close(pipe_feed[1]);
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execlp("sh", "sh", "-c", cmd, NULL);
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return 1;
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}
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close(pipe_feed[0]);
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write_err = (write_in_full(pipe_feed[1], src, size) < 0);
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if (close(pipe_feed[1]))
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write_err = 1;
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if (write_err)
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error("cannot feed the input to external filter %s", cmd);
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status = finish_command(&child_process);
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if (status)
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error("external filter %s failed %d", cmd, -status);
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return (write_err || status);
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}
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static char *apply_filter(const char *path, const char *src,
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unsigned long *sizep, const char *cmd)
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{
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/*
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* Create a pipeline to have the command filter the buffer's
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* contents.
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*
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* (child --> cmd) --> us
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*/
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const int SLOP = 4096;
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int pipe_feed[2];
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int status;
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char *dst;
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unsigned long dstsize, dstalloc;
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struct child_process child_process;
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if (!cmd)
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return NULL;
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memset(&child_process, 0, sizeof(child_process));
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if (pipe(pipe_feed) < 0) {
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error("cannot create pipe to run external filter %s", cmd);
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return NULL;
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}
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fflush(NULL);
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child_process.pid = fork();
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if (child_process.pid < 0) {
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error("cannot fork to run external filter %s", cmd);
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close(pipe_feed[0]);
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close(pipe_feed[1]);
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return NULL;
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}
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if (!child_process.pid) {
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dup2(pipe_feed[1], 1);
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close(pipe_feed[0]);
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close(pipe_feed[1]);
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exit(filter_buffer(path, src, *sizep, cmd));
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}
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close(pipe_feed[1]);
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dstalloc = *sizep;
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dst = xmalloc(dstalloc);
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dstsize = 0;
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while (1) {
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ssize_t numread = xread(pipe_feed[0], dst + dstsize,
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dstalloc - dstsize);
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if (numread <= 0) {
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if (!numread)
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break;
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error("read from external filter %s failed", cmd);
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free(dst);
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dst = NULL;
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break;
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}
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dstsize += numread;
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if (dstalloc <= dstsize + SLOP) {
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dstalloc = dstsize + SLOP;
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dst = xrealloc(dst, dstalloc);
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}
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}
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if (close(pipe_feed[0])) {
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error("read from external filter %s failed", cmd);
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free(dst);
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dst = NULL;
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}
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status = finish_command(&child_process);
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if (status) {
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error("external filter %s failed %d", cmd, -status);
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free(dst);
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dst = NULL;
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}
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if (dst)
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*sizep = dstsize;
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return dst;
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}
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static struct convert_driver {
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const char *name;
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struct convert_driver *next;
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char *smudge;
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char *clean;
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} *user_convert, **user_convert_tail;
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static int read_convert_config(const char *var, const char *value)
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{
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const char *ep, *name;
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int namelen;
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struct convert_driver *drv;
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/*
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* External conversion drivers are configured using
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* "filter.<name>.variable".
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*/
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if (prefixcmp(var, "filter.") || (ep = strrchr(var, '.')) == var + 6)
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return 0;
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name = var + 7;
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namelen = ep - name;
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for (drv = user_convert; drv; drv = drv->next)
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if (!strncmp(drv->name, name, namelen) && !drv->name[namelen])
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break;
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if (!drv) {
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char *namebuf;
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drv = xcalloc(1, sizeof(struct convert_driver));
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namebuf = xmalloc(namelen + 1);
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memcpy(namebuf, name, namelen);
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namebuf[namelen] = 0;
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drv->name = namebuf;
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drv->next = NULL;
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*user_convert_tail = drv;
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user_convert_tail = &(drv->next);
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}
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ep++;
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/*
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* filter.<name>.smudge and filter.<name>.clean specifies
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* the command line:
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*
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* command-line
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*
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* The command-line will not be interpolated in any way.
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*/
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if (!strcmp("smudge", ep)) {
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if (!value)
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return error("%s: lacks value", var);
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drv->smudge = strdup(value);
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return 0;
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}
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if (!strcmp("clean", ep)) {
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if (!value)
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return error("%s: lacks value", var);
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drv->clean = strdup(value);
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return 0;
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}
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return 0;
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}
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static void setup_convert_check(struct git_attr_check *check)
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{
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static struct git_attr *attr_crlf;
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static struct git_attr *attr_ident;
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static struct git_attr *attr_filter;
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if (!attr_crlf) {
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attr_crlf = git_attr("crlf", 4);
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attr_ident = git_attr("ident", 5);
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attr_filter = git_attr("filter", 6);
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user_convert_tail = &user_convert;
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git_config(read_convert_config);
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}
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check[0].attr = attr_crlf;
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check[1].attr = attr_ident;
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check[2].attr = attr_filter;
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}
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static int count_ident(const char *cp, unsigned long size)
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{
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/*
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* "$Id: 0000000000000000000000000000000000000000 $" <=> "$Id$"
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*/
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int cnt = 0;
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char ch;
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while (size) {
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ch = *cp++;
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size--;
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if (ch != '$')
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continue;
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if (size < 3)
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break;
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if (memcmp("Id", cp, 2))
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continue;
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ch = cp[2];
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cp += 3;
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size -= 3;
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if (ch == '$')
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cnt++; /* $Id$ */
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if (ch != ':')
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continue;
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/*
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* "$Id: ... "; scan up to the closing dollar sign and discard.
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*/
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while (size) {
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ch = *cp++;
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size--;
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if (ch == '$') {
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cnt++;
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break;
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}
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}
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}
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return cnt;
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}
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static char *ident_to_git(const char *path, const char *src, unsigned long *sizep, int ident)
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{
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int cnt;
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unsigned long size;
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char *dst, *buf;
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if (!ident)
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return NULL;
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size = *sizep;
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cnt = count_ident(src, size);
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if (!cnt)
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return NULL;
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buf = xmalloc(size);
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for (dst = buf; size; size--) {
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char ch = *src++;
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*dst++ = ch;
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if ((ch == '$') && (3 <= size) &&
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!memcmp("Id:", src, 3)) {
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unsigned long rem = size - 3;
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const char *cp = src + 3;
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do {
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ch = *cp++;
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if (ch == '$')
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break;
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rem--;
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} while (rem);
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if (!rem)
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continue;
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memcpy(dst, "Id$", 3);
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dst += 3;
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size -= (cp - src);
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src = cp;
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}
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}
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*sizep = dst - buf;
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return buf;
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}
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static char *ident_to_worktree(const char *path, const char *src, unsigned long *sizep, int ident)
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{
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int cnt;
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unsigned long size;
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char *dst, *buf;
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unsigned char sha1[20];
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if (!ident)
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return NULL;
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size = *sizep;
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cnt = count_ident(src, size);
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if (!cnt)
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return NULL;
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hash_sha1_file(src, size, "blob", sha1);
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buf = xmalloc(size + cnt * 43);
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for (dst = buf; size; size--) {
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const char *cp;
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/* Fetch next source character, move the pointer on */
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char ch = *src++;
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/* Copy the current character to the destination */
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*dst++ = ch;
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/* If the current character is "$" or there are less than three
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* remaining bytes or the two bytes following this one are not
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* "Id", then simply read the next character */
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if ((ch != '$') || (size < 3) || memcmp("Id", src, 2))
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continue;
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/*
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* Here when
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* - There are more than 2 bytes remaining
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* - The current three bytes are "$Id"
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* with
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* - ch == "$"
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* - src[0] == "I"
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*/
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/*
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* It's possible that an expanded Id has crept its way into the
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* repository, we cope with that by stripping the expansion out
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*/
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if (src[2] == ':') {
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/* Expanded keywords have "$Id:" at the front */
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/* discard up to but not including the closing $ */
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unsigned long rem = size - 3;
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/* Point at first byte after the ":" */
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cp = src + 3;
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/*
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* Throw away characters until either
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* - we reach a "$"
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* - we run out of bytes (rem == 0)
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*/
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do {
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ch = *cp;
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if (ch == '$')
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break;
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cp++;
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rem--;
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} while (rem);
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/* If the above finished because it ran out of characters, then
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* this is an incomplete keyword, so don't run the expansion */
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if (!rem)
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continue;
|
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} else if (src[2] == '$')
|
|
cp = src + 2;
|
|
else
|
|
/* Anything other than "$Id:XXX$" or $Id$ and we skip the
|
|
* expansion */
|
|
continue;
|
|
|
|
/* cp is now pointing at the last $ of the keyword */
|
|
|
|
memcpy(dst, "Id: ", 4);
|
|
dst += 4;
|
|
memcpy(dst, sha1_to_hex(sha1), 40);
|
|
dst += 40;
|
|
*dst++ = ' ';
|
|
|
|
/* Adjust for the characters we've discarded */
|
|
size -= (cp - src);
|
|
src = cp;
|
|
|
|
/* Copy the final "$" */
|
|
*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;
|
|
}
|