git/builtin/patch-id.c
Michael Schubert b9ab810b18 patch-id.c: use strbuf instead of a fixed buffer
get_one_patchid() uses a rather dumb heuristic to determine if the
passed buffer is part of the next commit. Whenever the first 40 bytes
are a valid hexadecimal sha1 representation, get_one_patchid() returns
next_sha1.

Once the current line is longer than the fixed buffer, this will break
(provided the additional bytes make a valid hexadecimal sha1). As a result
patch-id returns incorrect results. Instead, use strbuf and read one line
at a time.

Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Michael Schubert <mschub@elegosoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2011-09-22 09:35:07 -07:00

158 lines
3.1 KiB
C

#include "builtin.h"
static void flush_current_id(int patchlen, unsigned char *id, git_SHA_CTX *c)
{
unsigned char result[20];
char name[50];
if (!patchlen)
return;
git_SHA1_Final(result, c);
memcpy(name, sha1_to_hex(id), 41);
printf("%s %s\n", sha1_to_hex(result), name);
git_SHA1_Init(c);
}
static int remove_space(char *line)
{
char *src = line;
char *dst = line;
unsigned char c;
while ((c = *src++) != '\0') {
if (!isspace(c))
*dst++ = c;
}
return dst - line;
}
static int scan_hunk_header(const char *p, int *p_before, int *p_after)
{
static const char digits[] = "0123456789";
const char *q, *r;
int n;
q = p + 4;
n = strspn(q, digits);
if (q[n] == ',') {
q += n + 1;
n = strspn(q, digits);
}
if (n == 0 || q[n] != ' ' || q[n+1] != '+')
return 0;
r = q + n + 2;
n = strspn(r, digits);
if (r[n] == ',') {
r += n + 1;
n = strspn(r, digits);
}
if (n == 0)
return 0;
*p_before = atoi(q);
*p_after = atoi(r);
return 1;
}
static int get_one_patchid(unsigned char *next_sha1, git_SHA_CTX *ctx, struct strbuf *line_buf)
{
int patchlen = 0, found_next = 0;
int before = -1, after = -1;
while (strbuf_getwholeline(line_buf, stdin, '\n') != EOF) {
char *line = line_buf->buf;
char *p = line;
int len;
if (!memcmp(line, "diff-tree ", 10))
p += 10;
else if (!memcmp(line, "commit ", 7))
p += 7;
else if (!memcmp(line, "From ", 5))
p += 5;
else if (!memcmp(line, "\\ ", 2) && 12 < strlen(line))
continue;
if (!get_sha1_hex(p, next_sha1)) {
found_next = 1;
break;
}
/* Ignore commit comments */
if (!patchlen && memcmp(line, "diff ", 5))
continue;
/* Parsing diff header? */
if (before == -1) {
if (!memcmp(line, "index ", 6))
continue;
else if (!memcmp(line, "--- ", 4))
before = after = 1;
else if (!isalpha(line[0]))
break;
}
/* Looking for a valid hunk header? */
if (before == 0 && after == 0) {
if (!memcmp(line, "@@ -", 4)) {
/* Parse next hunk, but ignore line numbers. */
scan_hunk_header(line, &before, &after);
continue;
}
/* Split at the end of the patch. */
if (memcmp(line, "diff ", 5))
break;
/* Else we're parsing another header. */
before = after = -1;
}
/* If we get here, we're inside a hunk. */
if (line[0] == '-' || line[0] == ' ')
before--;
if (line[0] == '+' || line[0] == ' ')
after--;
/* Compute the sha without whitespace */
len = remove_space(line);
patchlen += len;
git_SHA1_Update(ctx, line, len);
}
if (!found_next)
hashclr(next_sha1);
return patchlen;
}
static void generate_id_list(void)
{
unsigned char sha1[20], n[20];
git_SHA_CTX ctx;
int patchlen;
struct strbuf line_buf = STRBUF_INIT;
git_SHA1_Init(&ctx);
hashclr(sha1);
while (!feof(stdin)) {
patchlen = get_one_patchid(n, &ctx, &line_buf);
flush_current_id(patchlen, sha1, &ctx);
hashcpy(sha1, n);
}
strbuf_release(&line_buf);
}
static const char patch_id_usage[] = "git patch-id < patch";
int cmd_patch_id(int argc, const char **argv, const char *prefix)
{
if (argc != 1)
usage(patch_id_usage);
generate_id_list();
return 0;
}