[thirdparty/git.git] / diff-tree.c

#include <ctype.h>
#include "cache.h"
#include "diff.h"

static int silent = 0;
static int verbose_header = 0;
static int ignore_merges = 1;
static int recursive = 0;
static int read_stdin = 0;
static int line_termination = '\n';
static int generate_patch = 0;
static const char *header = NULL;
static const char *header_prefix = "";

// What paths are we interested in?
static int nr_paths = 0;
static char **paths = NULL;
static int *pathlens = NULL;

static int diff_tree_sha1(const unsigned char *old, const unsigned char *new, const char *base);

static void update_tree_entry(void **bufp, unsigned long *sizep)
{
	void *buf = *bufp;
	unsigned long size = *sizep;
	int len = strlen(buf) + 1 + 20;

	if (size < len)
		die("corrupt tree file");
	*bufp = buf + len;
	*sizep = size - len;
}

static const unsigned char *extract(void *tree, unsigned long size, const char **pathp, unsigned int *modep)
{
	int len = strlen(tree)+1;
	const unsigned char *sha1 = tree + len;
	const char *path = strchr(tree, ' ');

	if (!path || size < len + 20 || sscanf(tree, "%o", modep) != 1)
		die("corrupt tree file");
	*pathp = path+1;
	return sha1;
}

static char *malloc_base(const char *base, const char *path, int pathlen)
{
	int baselen = strlen(base);
	char *newbase = xmalloc(baselen + pathlen + 2);
	memcpy(newbase, base, baselen);
	memcpy(newbase + baselen, path, pathlen);
	memcpy(newbase + baselen + pathlen, "/", 2);
	return newbase;
}

static void show_file(const char *prefix, void *tree, unsigned long size, const char *base);
static void show_tree(const char *prefix, void *tree, unsigned long size, const char *base);

/* A file entry went away or appeared */
static void show_file(const char *prefix, void *tree, unsigned long size, const char *base)
{
	unsigned mode;
	const char *path;
	const unsigned char *sha1 = extract(tree, size, &path, &mode);

	if (header) {
		printf("%s", header);
		header = NULL;
	}

	if (silent)
		return;

	if (recursive && S_ISDIR(mode)) {
		char type[20];
		unsigned long size;
		char *newbase = malloc_base(base, path, strlen(path));
		void *tree;

		tree = read_sha1_file(sha1, type, &size);
		if (!tree || strcmp(type, "tree"))
			die("corrupt tree sha %s", sha1_to_hex(sha1));

		show_tree(prefix, tree, size, newbase);
		
		free(tree);
		free(newbase);
		return;
	}

	if (generate_patch) {
		if (!S_ISDIR(mode))
			diff_addremove(prefix[0], mode, sha1, base, path);
	}
	else
		printf("%s%06o\t%s\t%s\t%s%s%c", prefix, mode,
		       S_ISDIR(mode) ? "tree" : "blob",
		       sha1_to_hex(sha1), base, path,
		       line_termination);
}

static int compare_tree_entry(void *tree1, unsigned long size1, void *tree2, unsigned long size2, const char *base)
{
	unsigned mode1, mode2;
	const char *path1, *path2;
	const unsigned char *sha1, *sha2;
	int cmp, pathlen1, pathlen2;
	char old_sha1_hex[50];

	sha1 = extract(tree1, size1, &path1, &mode1);
	sha2 = extract(tree2, size2, &path2, &mode2);

	pathlen1 = strlen(path1);
	pathlen2 = strlen(path2);
	cmp = cache_name_compare(path1, pathlen1, path2, pathlen2);
	if (cmp < 0) {
		show_file("-", tree1, size1, base);
		return -1;
	}
	if (cmp > 0) {
		show_file("+", tree2, size2, base);
		return 1;
	}
	if (!memcmp(sha1, sha2, 20) && mode1 == mode2)
		return 0;

	/*
	 * If the filemode has changed to/from a directory from/to a regular
	 * file, we need to consider it a remove and an add.
	 */
	if (S_ISDIR(mode1) != S_ISDIR(mode2)) {
		show_file("-", tree1, size1, base);
		show_file("+", tree2, size2, base);
		return 0;
	}

	if (recursive && S_ISDIR(mode1)) {
		int retval;
		char *newbase = malloc_base(base, path1, pathlen1);
		retval = diff_tree_sha1(sha1, sha2, newbase);
		free(newbase);
		return retval;
	}

	if (header) {
		printf("%s", header);
		header = NULL;
	}
	if (silent)
		return 0;

	if (generate_patch) {
		if (!S_ISDIR(mode1))
			diff_change(mode1, mode2, sha1, sha2, base, path1);
	}
	else {
		strcpy(old_sha1_hex, sha1_to_hex(sha1));
		printf("*%06o->%06o\t%s\t%s->%s\t%s%s%c", mode1, mode2,
		       S_ISDIR(mode1) ? "tree" : "blob",
		       old_sha1_hex, sha1_to_hex(sha2), base, path1,
		       line_termination);
	}
	return 0;
}

static int interesting(void *tree, unsigned long size, const char *base)
{
	const char *path;
	unsigned mode;
	int i;
	int baselen, pathlen;

	if (!nr_paths)
		return 1;

	(void)extract(tree, size, &path, &mode);

	pathlen = strlen(path);
	baselen = strlen(base);

	for (i=0; i < nr_paths; i++) {
		const char *match = paths[i];
		int matchlen = pathlens[i];

		if (baselen >= matchlen) {
			/* If it doesn't match, move along... */
			if (strncmp(base, match, matchlen))
				continue;

			/* The base is a subdirectory of a path which was specified. */
			return 1;
		}

		/* Does the base match? */
		if (strncmp(base, match, baselen))
			continue;

		match += baselen;
		matchlen -= baselen;

		if (pathlen > matchlen)
			continue;

		if (matchlen > pathlen) {
			if (match[pathlen] != '/')
				continue;
		}

		if (strncmp(path, match, pathlen))
			continue;

		return 1;
	}
	return 0; /* No matches */
}

/* A whole sub-tree went away or appeared */
static void show_tree(const char *prefix, void *tree, unsigned long size, const char *base)
{
	while (size) {
		if (interesting(tree, size, base))
			show_file(prefix, tree, size, base);
		update_tree_entry(&tree, &size);
	}
}

static int diff_tree(void *tree1, unsigned long size1, void *tree2, unsigned long size2, const char *base)
{
	while (size1 | size2) {
		if (nr_paths && size1 && !interesting(tree1, size1, base)) {
			update_tree_entry(&tree1, &size1);
			continue;
		}
		if (nr_paths && size2 && !interesting(tree2, size2, base)) {
			update_tree_entry(&tree2, &size2);
			continue;
		}
		if (!size1) {
			show_file("+", tree2, size2, base);
			update_tree_entry(&tree2, &size2);
			continue;
		}
		if (!size2) {
			show_file("-", tree1, size1, base);
			update_tree_entry(&tree1, &size1);
			continue;
		}
		switch (compare_tree_entry(tree1, size1, tree2, size2, base)) {
		case -1:
			update_tree_entry(&tree1, &size1);
			continue;
		case 0:
			update_tree_entry(&tree1, &size1);
			/* Fallthrough */
		case 1:
			update_tree_entry(&tree2, &size2);
			continue;
		}
		die("diff-tree: internal error");
	}
	return 0;
}

static int diff_tree_sha1(const unsigned char *old, const unsigned char *new, const char *base)
{
	void *tree1, *tree2;
	unsigned long size1, size2;
	int retval;

	tree1 = read_object_with_reference(old, "tree", &size1, 0);
	if (!tree1)
		die("unable to read source tree (%s)", sha1_to_hex(old));
	tree2 = read_object_with_reference(new, "tree", &size2, 0);
	if (!tree2)
		die("unable to read destination tree (%s)", sha1_to_hex(new));
	retval = diff_tree(tree1, size1, tree2, size2, base);
	free(tree1);
	free(tree2);
	return retval;
}

static int get_one_line(const char *msg, unsigned long len)
{
	int ret = 0;

	while (len--) {
		ret++;
		if (*msg++ == '\n')
			break;
	}
	return ret;
}

static int add_author_info(char *buf, const char *line, int len)
{
	char *date;
	unsigned int namelen;
	unsigned long time;
	int tz;

	line += strlen("author ");
	date = strchr(line, '>');
	if (!date)
		return 0;
	namelen = ++date - line;
	time = strtoul(date, &date, 10);
	tz = strtol(date, NULL, 10);

	return sprintf(buf, "Author: %.*s\nDate:   %s\n",
		namelen, line,
		show_date(time, tz));
}

static char *generate_header(const char *commit, const char *parent, const char *msg, unsigned long len)
{
	static char this_header[1000];
	int offset;

	offset = sprintf(this_header, "%s%s (from %s)\n", header_prefix, commit, parent);
	if (verbose_header) {
		int hdr = 1;

		for (;;) {
			const char *line = msg;
			int linelen = get_one_line(msg, len);

			if (!linelen)
				break;
			if (offset + linelen + 10 > sizeof(this_header))
				break;

			msg += linelen;
			len -= linelen;
			if (linelen == 1)
				hdr = 0;
			if (hdr) {
				if (!memcmp(line, "author ", 7))
					offset += add_author_info(this_header + offset, line, linelen);
				continue;
			}
			memset(this_header + offset, ' ', 4);
			memcpy(this_header + offset + 4, line, linelen);
			offset += linelen + 4;
		}
		this_header[offset++] = '\n';
		this_header[offset] = 0;
	}

	return this_header;
}

static int diff_tree_commit(const unsigned char *commit, const char *name)
{
	unsigned long size, offset;
	char *buf = read_object_with_reference(commit, "commit", &size, NULL);

	if (!buf)
		return -1;

	/* More than one parent? */
	if (ignore_merges) {
		if (!memcmp(buf + 46 + 48, "parent ", 7))
			return 0;
	}

	if (!name) {
		static char commit_name[60];
		strcpy(commit_name, sha1_to_hex(commit));
		name = commit_name;
	}

	offset = 46;
	while (offset + 48 < size && !memcmp(buf + offset, "parent ", 7)) {
		unsigned char parent[20];
		if (get_sha1_hex(buf + offset + 7, parent))
			return -1;
		header = generate_header(name, sha1_to_hex(parent), buf, size);
		diff_tree_sha1(parent, commit, "");
		if (!header && verbose_header)
			header_prefix = "\ndiff-tree ";
		offset += 48;
	}
	return 0;
}

static int diff_tree_stdin(char *line)
{
	int len = strlen(line);
	unsigned char commit[20], parent[20];
	static char this_header[1000];

	if (!len || line[len-1] != '\n')
		return -1;
	line[len-1] = 0;
	if (get_sha1_hex(line, commit))
		return -1;
	if (isspace(line[40]) && !get_sha1_hex(line+41, parent)) {
		line[40] = 0;
		line[81] = 0;
		sprintf(this_header, "%s (from %s)\n", line, line+41);
		header = this_header;
		return diff_tree_sha1(parent, commit, "");
	}
	line[40] = 0;
	return diff_tree_commit(commit, line);
}

static char *diff_tree_usage =
"diff-tree [-p] [-r] [-z] [--stdin] [-m] [-s] [-v] <tree sha1> <tree sha1>";

int main(int argc, char **argv)
{
	int nr_sha1;
	char line[1000];
	unsigned char sha1[2][20];

	nr_sha1 = 0;
	for (;;) {
		char *arg;

		argv++;
		argc--;
		arg = *argv;
		if (!arg)
			break;

		if (*arg != '-') {
			if (nr_sha1 < 2 && !get_sha1(arg, sha1[nr_sha1])) {
				nr_sha1++;
				continue;
			}
			break;
		}

		if (!strcmp(arg, "--")) {
			argv++;
			argc--;
			break;
		}
		if (!strcmp(arg, "-r")) {
			recursive = 1;
			continue;
		}
		if (!strcmp(arg, "-p")) {
			recursive = generate_patch = 1;
			continue;
		}
		if (!strcmp(arg, "-z")) {
			line_termination = '\0';
			continue;
		}
		if (!strcmp(arg, "-m")) {
			ignore_merges = 0;
			continue;
		}
		if (!strcmp(arg, "-s")) {
			silent = 1;
			continue;
		}
		if (!strcmp(arg, "-v")) {
			verbose_header = 1;
			header_prefix = "diff-tree ";
			continue;
		}
		if (!strcmp(arg, "--stdin")) {
			read_stdin = 1;
			continue;
		}
		usage(diff_tree_usage);
	}

	if (argc > 0) {
		int i;

		paths = argv;
		nr_paths = argc;
		pathlens = xmalloc(nr_paths * sizeof(int));
		for (i=0; i<nr_paths; i++)
			pathlens[i] = strlen(paths[i]);
	}

	switch (nr_sha1) {
	case 0:
		if (!read_stdin)
			usage(diff_tree_usage);
		break;
	case 1:
		diff_tree_commit(sha1[0], NULL);
		break;
	case 2:
		diff_tree_sha1(sha1[0], sha1[1], "");
		break;
	}

	if (!read_stdin)
		return 0;

	while (fgets(line, sizeof(line), stdin))
		diff_tree_stdin(line);

	return 0;
}
Commit	Line	Data
e0965d83	1	#include <ctype.h>
9174026c	2	#include "cache.h"
3ebfd4aa	3	#include "diff.h"
9174026c	4
f4f21ce3	5	static int silent = 0;
cee99d22	6	static int verbose_header = 0;
e0965d83	7	static int ignore_merges = 1;
73134b6d	8	static int recursive = 0;
e0965d83	9	static int read_stdin = 0;
6cbd72f8	10	static int line_termination = '\n';
3ebfd4aa	11	static int generate_patch = 0;
f4f21ce3	12	static const char *header = NULL;
cee99d22	13	static const char *header_prefix = "";
9174026c	14
c5b42386 LT	15	// What paths are we interested in?
	16	static int nr_paths = 0;
	17	static char **paths = NULL;
	18	static int *pathlens = NULL;
	19
eeb79916	20	static int diff_tree_sha1(const unsigned char old, const unsigned char new, const char *base);
73134b6d LT	21
73134b6d LT	22	static void update_tree_entry(void *bufp, unsigned long sizep)
9174026c LT	23	{
	24	void buf = bufp;
	25	unsigned long size = *sizep;
	26	int len = strlen(buf) + 1 + 20;
	27
	28	if (size < len)
2de381f9	29	die("corrupt tree file");
9174026c LT	30	*bufp = buf + len;
9174026c LT	31	*sizep = size - len;
9174026c LT	32	}
	33
	34	static const unsigned char extract(void tree, unsigned long size, const char *pathp, unsigned int modep)
	35	{
	36	int len = strlen(tree)+1;
	37	const unsigned char *sha1 = tree + len;
	38	const char *path = strchr(tree, ' ');
	39
	40	if (!path \|\| size < len + 20 \|\| sscanf(tree, "%o", modep) != 1)
2de381f9	41	die("corrupt tree file");
9174026c LT	42	*pathp = path+1;
	43	return sha1;
	44	}
	45
262e82b4 LT	46	static char malloc_base(const char base, const char *path, int pathlen)
	47	{
	48	int baselen = strlen(base);
812666c8	49	char *newbase = xmalloc(baselen + pathlen + 2);
262e82b4 LT	50	memcpy(newbase, base, baselen);
	51	memcpy(newbase + baselen, path, pathlen);
	52	memcpy(newbase + baselen + pathlen, "/", 2);
	53	return newbase;
	54	}
	55
	56	static void show_file(const char prefix, void tree, unsigned long size, const char *base);
ed1a368b	57	static void show_tree(const char prefix, void tree, unsigned long size, const char *base);
262e82b4 LT	58
262e82b4 LT	59	/* A file entry went away or appeared */
73134b6d	60	static void show_file(const char prefix, void tree, unsigned long size, const char *base)
9174026c LT	61	{
	62	unsigned mode;
	63	const char *path;
	64	const unsigned char *sha1 = extract(tree, size, &path, &mode);
262e82b4	65
f4f21ce3 LT	66	if (header) {
	67	printf("%s", header);
	68	header = NULL;
	69	}
	70
	71	if (silent)
	72	return;
	73
262e82b4 LT	74	if (recursive && S_ISDIR(mode)) {
	75	char type[20];
	76	unsigned long size;
	77	char *newbase = malloc_base(base, path, strlen(path));
	78	void *tree;
	79
	80	tree = read_sha1_file(sha1, type, &size);
	81	if (!tree \|\| strcmp(type, "tree"))
2de381f9	82	die("corrupt tree sha %s", sha1_to_hex(sha1));
262e82b4 LT	83
	84	show_tree(prefix, tree, size, newbase);
	85
	86	free(tree);
	87	free(newbase);
	88	return;
	89	}
	90
3ebfd4aa JH	91	if (generate_patch) {
	92	if (!S_ISDIR(mode))
	93	diff_addremove(prefix[0], mode, sha1, base, path);
	94	}
	95	else
	96	printf("%s%06o\t%s\t%s\t%s%s%c", prefix, mode,
	97	S_ISDIR(mode) ? "tree" : "blob",
	98	sha1_to_hex(sha1), base, path,
	99	line_termination);
9174026c LT	100	}
9174026c LT	101
eeb79916	102	static int compare_tree_entry(void tree1, unsigned long size1, void tree2, unsigned long size2, const char *base)
9174026c LT	103	{
	104	unsigned mode1, mode2;
	105	const char path1, path2;
	106	const unsigned char sha1, sha2;
73134b6d	107	int cmp, pathlen1, pathlen2;
eeb79916	108	char old_sha1_hex[50];
9174026c LT	109
	110	sha1 = extract(tree1, size1, &path1, &mode1);
	111	sha2 = extract(tree2, size2, &path2, &mode2);
	112
73134b6d LT	113	pathlen1 = strlen(path1);
	114	pathlen2 = strlen(path2);
	115	cmp = cache_name_compare(path1, pathlen1, path2, pathlen2);
9174026c	116	if (cmp < 0) {
eeb79916	117	show_file("-", tree1, size1, base);
9174026c LT	118	return -1;
	119	}
	120	if (cmp > 0) {
eeb79916	121	show_file("+", tree2, size2, base);
9174026c LT	122	return 1;
	123	}
	124	if (!memcmp(sha1, sha2, 20) && mode1 == mode2)
	125	return 0;
262e82b4 LT	126
	127	/*
	128	* If the filemode has changed to/from a directory from/to a regular
aebb2679	129	* file, we need to consider it a remove and an add.
262e82b4 LT	130	*/
	131	if (S_ISDIR(mode1) != S_ISDIR(mode2)) {
	132	show_file("-", tree1, size1, base);
	133	show_file("+", tree2, size2, base);
	134	return 0;
	135	}
	136
	137	if (recursive && S_ISDIR(mode1)) {
eeb79916	138	int retval;
262e82b4	139	char *newbase = malloc_base(base, path1, pathlen1);
eeb79916 LT	140	retval = diff_tree_sha1(sha1, sha2, newbase);
	141	free(newbase);
	142	return retval;
73134b6d LT	143	}
73134b6d LT	144
f4f21ce3 LT	145	if (header) {
	146	printf("%s", header);
	147	header = NULL;
	148	}
	149	if (silent)
	150	return 0;
	151
3ebfd4aa JH	152	if (generate_patch) {
	153	if (!S_ISDIR(mode1))
	154	diff_change(mode1, mode2, sha1, sha2, base, path1);
	155	}
	156	else {
	157	strcpy(old_sha1_hex, sha1_to_hex(sha1));
	158	printf("*%06o->%06o\t%s\t%s->%s\t%s%s%c", mode1, mode2,
	159	S_ISDIR(mode1) ? "tree" : "blob",
	160	old_sha1_hex, sha1_to_hex(sha2), base, path1,
	161	line_termination);
	162	}
9174026c LT	163	return 0;
	164	}
	165
c5b42386 LT	166	static int interesting(void tree, unsigned long size, const char base)
	167	{
	168	const char *path;
	169	unsigned mode;
	170	int i;
	171	int baselen, pathlen;
	172
	173	if (!nr_paths)
	174	return 1;
	175
	176	(void)extract(tree, size, &path, &mode);
	177
	178	pathlen = strlen(path);
	179	baselen = strlen(base);
	180
	181	for (i=0; i < nr_paths; i++) {
	182	const char *match = paths[i];
	183	int matchlen = pathlens[i];
	184
	185	if (baselen >= matchlen) {
	186	/* If it doesn't match, move along... */
	187	if (strncmp(base, match, matchlen))
	188	continue;
	189
	190	/* The base is a subdirectory of a path which was specified. */
	191	return 1;
	192	}
	193
	194	/* Does the base match? */
	195	if (strncmp(base, match, baselen))
	196	continue;
	197
	198	match += baselen;
	199	matchlen -= baselen;
	200
	201	if (pathlen > matchlen)
	202	continue;
	203
cb6c8ed2 LT	204	if (matchlen > pathlen) {
	205	if (match[pathlen] != '/')
	206	continue;
	207	}
	208
c5b42386 LT	209	if (strncmp(path, match, pathlen))
	210	continue;
	211
	212	return 1;
	213	}
	214	return 0; /* No matches */
	215	}
	216
ed1a368b LT	217	/* A whole sub-tree went away or appeared */
	218	static void show_tree(const char prefix, void tree, unsigned long size, const char *base)
	219	{
	220	while (size) {
	221	if (interesting(tree, size, base))
	222	show_file(prefix, tree, size, base);
	223	update_tree_entry(&tree, &size);
	224	}
	225	}
	226
eeb79916	227	static int diff_tree(void tree1, unsigned long size1, void tree2, unsigned long size2, const char *base)
9174026c LT	228	{
9174026c LT	229	while (size1 \| size2) {
c5b42386 LT	230	if (nr_paths && size1 && !interesting(tree1, size1, base)) {
	231	update_tree_entry(&tree1, &size1);
	232	continue;
	233	}
	234	if (nr_paths && size2 && !interesting(tree2, size2, base)) {
	235	update_tree_entry(&tree2, &size2);
	236	continue;
	237	}
9174026c	238	if (!size1) {
eeb79916	239	show_file("+", tree2, size2, base);
9174026c LT	240	update_tree_entry(&tree2, &size2);
	241	continue;
	242	}
	243	if (!size2) {
eeb79916	244	show_file("-", tree1, size1, base);
9174026c LT	245	update_tree_entry(&tree1, &size1);
	246	continue;
	247	}
eeb79916	248	switch (compare_tree_entry(tree1, size1, tree2, size2, base)) {
9174026c LT	249	case -1:
	250	update_tree_entry(&tree1, &size1);
	251	continue;
	252	case 0:
	253	update_tree_entry(&tree1, &size1);
	254	/* Fallthrough */
	255	case 1:
	256	update_tree_entry(&tree2, &size2);
	257	continue;
	258	}
2de381f9	259	die("diff-tree: internal error");
9174026c LT	260	}
	261	return 0;
	262	}
	263
eeb79916	264	static int diff_tree_sha1(const unsigned char old, const unsigned char new, const char *base)
9174026c	265	{
9174026c LT	266	void tree1, tree2;
9174026c LT	267	unsigned long size1, size2;
73134b6d	268	int retval;
9174026c	269
40469ee9	270	tree1 = read_object_with_reference(old, "tree", &size1, 0);
c1fdf2a6	271	if (!tree1)
2de381f9	272	die("unable to read source tree (%s)", sha1_to_hex(old));
40469ee9	273	tree2 = read_object_with_reference(new, "tree", &size2, 0);
c1fdf2a6	274	if (!tree2)
2de381f9	275	die("unable to read destination tree (%s)", sha1_to_hex(new));
eeb79916	276	retval = diff_tree(tree1, size1, tree2, size2, base);
73134b6d LT	277	free(tree1);
	278	free(tree2);
	279	return retval;
	280	}
	281
cee99d22 LT	282	static int get_one_line(const char *msg, unsigned long len)
	283	{
	284	int ret = 0;
	285
	286	while (len--) {
	287	ret++;
	288	if (*msg++ == '\n')
	289	break;
	290	}
	291	return ret;
	292	}
	293
a02ebff6 LT	294	static int add_author_info(char buf, const char line, int len)
	295	{
	296	char *date;
	297	unsigned int namelen;
	298	unsigned long time;
	299	int tz;
	300
	301	line += strlen("author ");
	302	date = strchr(line, '>');
	303	if (!date)
	304	return 0;
	305	namelen = ++date - line;
	306	time = strtoul(date, &date, 10);
	307	tz = strtol(date, NULL, 10);
	308
	309	return sprintf(buf, "Author: %.*s\nDate: %s\n",
	310	namelen, line,
	311	show_date(time, tz));
	312	}
	313
cee99d22 LT	314	static char generate_header(const char commit, const char parent, const char msg, unsigned long len)
	315	{
	316	static char this_header[1000];
	317	int offset;
	318
	319	offset = sprintf(this_header, "%s%s (from %s)\n", header_prefix, commit, parent);
	320	if (verbose_header) {
	321	int hdr = 1;
	322
	323	for (;;) {
	324	const char *line = msg;
	325	int linelen = get_one_line(msg, len);
	326
	327	if (!linelen)
	328	break;
	329	if (offset + linelen + 10 > sizeof(this_header))
	330	break;
	331
	332	msg += linelen;
	333	len -= linelen;
	334	if (linelen == 1)
	335	hdr = 0;
a02ebff6 LT	336	if (hdr) {
	337	if (!memcmp(line, "author ", 7))
	338	offset += add_author_info(this_header + offset, line, linelen);
cee99d22	339	continue;
a02ebff6	340	}
cee99d22 LT	341	memset(this_header + offset, ' ', 4);
	342	memcpy(this_header + offset + 4, line, linelen);
	343	offset += linelen + 4;
	344	}
	345	this_header[offset++] = '\n';
	346	this_header[offset] = 0;
	347	}
	348
	349	return this_header;
	350	}
	351
b11645be	352	static int diff_tree_commit(const unsigned char commit, const char name)
e0965d83	353	{
e0965d83	354	unsigned long size, offset;
b11645be	355	char *buf = read_object_with_reference(commit, "commit", &size, NULL);
e0965d83	356
e0965d83 LT	357	if (!buf)
	358	return -1;
	359
	360	/* More than one parent? */
	361	if (ignore_merges) {
	362	if (!memcmp(buf + 46 + 48, "parent ", 7))
	363	return 0;
	364	}
	365
73848892 LT	366	if (!name) {
	367	static char commit_name[60];
	368	strcpy(commit_name, sha1_to_hex(commit));
	369	name = commit_name;
	370	}
	371
e0965d83 LT	372	offset = 46;
e0965d83 LT	373	while (offset + 48 < size && !memcmp(buf + offset, "parent ", 7)) {
b11645be	374	unsigned char parent[20];
e0965d83 LT	375	if (get_sha1_hex(buf + offset + 7, parent))
e0965d83 LT	376	return -1;
b11645be	377	header = generate_header(name, sha1_to_hex(parent), buf, size);
e0965d83	378	diff_tree_sha1(parent, commit, "");
cee99d22 LT	379	if (!header && verbose_header)
cee99d22 LT	380	header_prefix = "\ndiff-tree ";
e0965d83 LT	381	offset += 48;
e0965d83 LT	382	}
b11645be LT	383	return 0;
	384	}
	385
	386	static int diff_tree_stdin(char *line)
	387	{
	388	int len = strlen(line);
	389	unsigned char commit[20], parent[20];
	390	static char this_header[1000];
	391
	392	if (!len \|\| line[len-1] != '\n')
	393	return -1;
	394	line[len-1] = 0;
	395	if (get_sha1_hex(line, commit))
	396	return -1;
	397	if (isspace(line[40]) && !get_sha1_hex(line+41, parent)) {
	398	line[40] = 0;
	399	line[81] = 0;
	400	sprintf(this_header, "%s (from %s)\n", line, line+41);
	401	header = this_header;
	402	return diff_tree_sha1(parent, commit, "");
	403	}
	404	line[40] = 0;
	405	return diff_tree_commit(commit, line);
e0965d83 LT	406	}
e0965d83 LT	407
5aad72f2 JH	408	static char *diff_tree_usage =
5aad72f2 JH	409	"diff-tree [-p] [-r] [-z] [--stdin] [-m] [-s] [-v] <tree sha1> <tree sha1>";
c5bac17a	410
73134b6d LT	411	int main(int argc, char **argv)
73134b6d LT	412	{
0a8365a1	413	int nr_sha1;
e0965d83	414	char line[1000];
0a8365a1	415	unsigned char sha1[2][20];
73134b6d	416
0a8365a1	417	nr_sha1 = 0;
c5b42386	418	for (;;) {
e0965d83	419	char *arg;
c5b42386	420
e0965d83 LT	421	argv++;
	422	argc--;
	423	arg = *argv;
0a8365a1	424	if (!arg)
c5b42386 LT	425	break;
c5b42386 LT	426
0a8365a1 LT	427	if (*arg != '-') {
	428	if (nr_sha1 < 2 && !get_sha1(arg, sha1[nr_sha1])) {
	429	nr_sha1++;
	430	continue;
	431	}
	432	break;
	433	}
	434
	435	if (!strcmp(arg, "--")) {
e0965d83 LT	436	argv++;
	437	argc--;
	438	break;
	439	}
bf16c71e	440	if (!strcmp(arg, "-r")) {
73134b6d LT	441	recursive = 1;
	442	continue;
	443	}
3ebfd4aa	444	if (!strcmp(arg, "-p")) {
3a663fd9	445	recursive = generate_patch = 1;
3ebfd4aa JH	446	continue;
3ebfd4aa JH	447	}
6cbd72f8 LT	448	if (!strcmp(arg, "-z")) {
	449	line_termination = '\0';
	450	continue;
	451	}
e0965d83 LT	452	if (!strcmp(arg, "-m")) {
	453	ignore_merges = 0;
	454	continue;
	455	}
f4f21ce3 LT	456	if (!strcmp(arg, "-s")) {
	457	silent = 1;
	458	continue;
	459	}
cee99d22 LT	460	if (!strcmp(arg, "-v")) {
	461	verbose_header = 1;
	462	header_prefix = "diff-tree ";
	463	continue;
	464	}
e0965d83 LT	465	if (!strcmp(arg, "--stdin")) {
	466	read_stdin = 1;
	467	continue;
	468	}
c5bac17a	469	usage(diff_tree_usage);
73134b6d LT	470	}
73134b6d LT	471
e0965d83	472	if (argc > 0) {
c5b42386 LT	473	int i;
c5b42386 LT	474
e0965d83 LT	475	paths = argv;
e0965d83 LT	476	nr_paths = argc;
812666c8	477	pathlens = xmalloc(nr_paths * sizeof(int));
c5b42386 LT	478	for (i=0; i<nr_paths; i++)
	479	pathlens[i] = strlen(paths[i]);
	480	}
	481
0a8365a1 LT	482	switch (nr_sha1) {
	483	case 0:
	484	if (!read_stdin)
	485	usage(diff_tree_usage);
	486	break;
	487	case 1:
73848892	488	diff_tree_commit(sha1[0], NULL);
0a8365a1 LT	489	break;
	490	case 2:
	491	diff_tree_sha1(sha1[0], sha1[1], "");
	492	break;
	493	}
	494
e0965d83	495	if (!read_stdin)
0a8365a1	496	return 0;
e0965d83 LT	497
	498	while (fgets(line, sizeof(line), stdin))
	499	diff_tree_stdin(line);
	500
	501	return 0;
9174026c	502	}