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

#include "cache.h"
#include "range-diff.h"
#include "string-list.h"
#include "run-command.h"
#include "strvec.h"
#include "hashmap.h"
#include "xdiff-interface.h"
#include "linear-assignment.h"
#include "diffcore.h"
#include "commit.h"
#include "pretty.h"
#include "userdiff.h"
#include "apply.h"

struct patch_util {
	/* For the search for an exact match */
	struct hashmap_entry e;
	const char *diff, *patch;

	int i, shown;
	int diffsize;
	size_t diff_offset;
	/* the index of the matching item in the other branch, or -1 */
	int matching;
	struct object_id oid;
};

static size_t find_end_of_line(char *buffer, unsigned long size)
{
	char *eol = memchr(buffer, '\n', size);

	if (!eol)
		return size;

	*eol = '\0';
	return eol + 1 - buffer;
}

/*
 * Reads the patches into a string list, with the `util` field being populated
 * as struct object_id (will need to be free()d).
 */
static int read_patches(const char *range, struct string_list *list,
			const struct strvec *other_arg)
{
	struct child_process cp = CHILD_PROCESS_INIT;
	struct strbuf buf = STRBUF_INIT, contents = STRBUF_INIT;
	struct patch_util *util = NULL;
	int in_header = 1;
	char *line, *current_filename = NULL;
	int offset, len;
	size_t size;

	strvec_pushl(&cp.args, "log", "--no-color", "-p", "--no-merges",
		     "--reverse", "--date-order", "--decorate=no",
		     "--no-prefix",
		     /*
		      * Choose indicators that are not used anywhere
		      * else in diffs, but still look reasonable
		      * (e.g. will not be confusing when debugging)
		      */
		     "--output-indicator-new=>",
		     "--output-indicator-old=<",
		     "--output-indicator-context=#",
		     "--no-abbrev-commit",
		     "--pretty=medium",
		     "--notes",
		     NULL);
	if (other_arg)
		strvec_pushv(&cp.args, other_arg->v);
	strvec_push(&cp.args, range);
	cp.out = -1;
	cp.no_stdin = 1;
	cp.git_cmd = 1;

	if (start_command(&cp))
		return error_errno(_("could not start `log`"));
	if (strbuf_read(&contents, cp.out, 0) < 0) {
		error_errno(_("could not read `log` output"));
		finish_command(&cp);
		return -1;
	}
	if (finish_command(&cp))
		return -1;

	line = contents.buf;
	size = contents.len;
	for (offset = 0; size > 0; offset += len, size -= len, line += len) {
		const char *p;

		len = find_end_of_line(line, size);
		line[len - 1] = '\0';
		if (skip_prefix(line, "commit ", &p)) {
			if (util) {
				string_list_append(list, buf.buf)->util = util;
				strbuf_reset(&buf);
			}
			util = xcalloc(sizeof(*util), 1);
			if (get_oid(p, &util->oid)) {
				error(_("could not parse commit '%s'"), p);
				free(util);
				free(current_filename);
				string_list_clear(list, 1);
				strbuf_release(&buf);
				strbuf_release(&contents);
				return -1;
			}
			util->matching = -1;
			in_header = 1;
			continue;
		}

		if (!util) {
			error(_("could not parse first line of `log` output: "
				"did not start with 'commit ': '%s'"),
			      line);
			free(current_filename);
			string_list_clear(list, 1);
			strbuf_release(&buf);
			strbuf_release(&contents);
			return -1;
		}

		if (starts_with(line, "diff --git")) {
			struct patch patch = { 0 };
			struct strbuf root = STRBUF_INIT;
			int linenr = 0;
			int orig_len;

			in_header = 0;
			strbuf_addch(&buf, '\n');
			if (!util->diff_offset)
				util->diff_offset = buf.len;
			line[len - 1] = '\n';
			orig_len = len;
			len = parse_git_diff_header(&root, &linenr, 0, line,
						    len, size, &patch);
			if (len < 0) {
				error(_("could not parse git header '%.*s'"),
				      orig_len, line);
				free(util);
				free(current_filename);
				string_list_clear(list, 1);
				strbuf_release(&buf);
				strbuf_release(&contents);
				return -1;
			}
			strbuf_addstr(&buf, " ## ");
			if (patch.is_new > 0)
				strbuf_addf(&buf, "%s (new)", patch.new_name);
			else if (patch.is_delete > 0)
				strbuf_addf(&buf, "%s (deleted)", patch.old_name);
			else if (patch.is_rename)
				strbuf_addf(&buf, "%s => %s", patch.old_name, patch.new_name);
			else
				strbuf_addstr(&buf, patch.new_name);

			free(current_filename);
			if (patch.is_delete > 0)
				current_filename = xstrdup(patch.old_name);
			else
				current_filename = xstrdup(patch.new_name);

			if (patch.new_mode && patch.old_mode &&
			    patch.old_mode != patch.new_mode)
				strbuf_addf(&buf, " (mode change %06o => %06o)",
					    patch.old_mode, patch.new_mode);

			strbuf_addstr(&buf, " ##");
		} else if (in_header) {
			if (starts_with(line, "Author: ")) {
				strbuf_addstr(&buf, " ## Metadata ##\n");
				strbuf_addstr(&buf, line);
				strbuf_addstr(&buf, "\n\n");
				strbuf_addstr(&buf, " ## Commit message ##\n");
			} else if (starts_with(line, "Notes") &&
				   line[strlen(line) - 1] == ':') {
				strbuf_addstr(&buf, "\n\n");
				/* strip the trailing colon */
				strbuf_addf(&buf, " ## %.*s ##\n",
					    (int)(strlen(line) - 1), line);
			} else if (starts_with(line, "    ")) {
				p = line + len - 2;
				while (isspace(*p) && p >= line)
					p--;
				strbuf_add(&buf, line, p - line + 1);
				strbuf_addch(&buf, '\n');
			}
			continue;
		} else if (skip_prefix(line, "@@ ", &p)) {
			p = strstr(p, "@@");
			strbuf_addstr(&buf, "@@");
			if (current_filename && p[2])
				strbuf_addf(&buf, " %s:", current_filename);
			if (p)
				strbuf_addstr(&buf, p + 2);
		} else if (!line[0])
			/*
			 * A completely blank (not ' \n', which is context)
			 * line is not valid in a diff.  We skip it
			 * silently, because this neatly handles the blank
			 * separator line between commits in git-log
			 * output.
			 */
			continue;
		else if (line[0] == '>') {
			strbuf_addch(&buf, '+');
			strbuf_addstr(&buf, line + 1);
		} else if (line[0] == '<') {
			strbuf_addch(&buf, '-');
			strbuf_addstr(&buf, line + 1);
		} else if (line[0] == '#') {
			strbuf_addch(&buf, ' ');
			strbuf_addstr(&buf, line + 1);
		} else {
			strbuf_addch(&buf, ' ');
			strbuf_addstr(&buf, line);
		}

		strbuf_addch(&buf, '\n');
		util->diffsize++;
	}
	strbuf_release(&contents);

	if (util)
		string_list_append(list, buf.buf)->util = util;
	strbuf_release(&buf);
	free(current_filename);

	return 0;
}

static int patch_util_cmp(const void *dummy, const struct patch_util *a,
			  const struct patch_util *b, const char *keydata)
{
	return strcmp(a->diff, keydata ? keydata : b->diff);
}

static void find_exact_matches(struct string_list *a, struct string_list *b)
{
	struct hashmap map = HASHMAP_INIT((hashmap_cmp_fn)patch_util_cmp, NULL);
	int i;

	/* First, add the patches of a to a hash map */
	for (i = 0; i < a->nr; i++) {
		struct patch_util *util = a->items[i].util;

		util->i = i;
		util->patch = a->items[i].string;
		util->diff = util->patch + util->diff_offset;
		hashmap_entry_init(&util->e, strhash(util->diff));
		hashmap_add(&map, &util->e);
	}

	/* Now try to find exact matches in b */
	for (i = 0; i < b->nr; i++) {
		struct patch_util *util = b->items[i].util, *other;

		util->i = i;
		util->patch = b->items[i].string;
		util->diff = util->patch + util->diff_offset;
		hashmap_entry_init(&util->e, strhash(util->diff));
		other = hashmap_remove_entry(&map, util, e, NULL);
		if (other) {
			if (other->matching >= 0)
				BUG("already assigned!");

			other->matching = i;
			util->matching = other->i;
		}
	}

	hashmap_clear(&map);
}

static void diffsize_consume(void *data, char *line, unsigned long len)
{
	(*(int *)data)++;
}

static void diffsize_hunk(void *data, long ob, long on, long nb, long nn,
			  const char *funcline, long funclen)
{
	diffsize_consume(data, NULL, 0);
}

static int diffsize(const char *a, const char *b)
{
	xpparam_t pp = { 0 };
	xdemitconf_t cfg = { 0 };
	mmfile_t mf1, mf2;
	int count = 0;

	mf1.ptr = (char *)a;
	mf1.size = strlen(a);
	mf2.ptr = (char *)b;
	mf2.size = strlen(b);

	cfg.ctxlen = 3;
	if (!xdi_diff_outf(&mf1, &mf2,
			   diffsize_hunk, diffsize_consume, &count,
			   &pp, &cfg))
		return count;

	error(_("failed to generate diff"));
	return COST_MAX;
}

static void get_correspondences(struct string_list *a, struct string_list *b,
				int creation_factor)
{
	int n = a->nr + b->nr;
	int *cost, c, *a2b, *b2a;
	int i, j;

	ALLOC_ARRAY(cost, st_mult(n, n));
	ALLOC_ARRAY(a2b, n);
	ALLOC_ARRAY(b2a, n);

	for (i = 0; i < a->nr; i++) {
		struct patch_util *a_util = a->items[i].util;

		for (j = 0; j < b->nr; j++) {
			struct patch_util *b_util = b->items[j].util;

			if (a_util->matching == j)
				c = 0;
			else if (a_util->matching < 0 && b_util->matching < 0)
				c = diffsize(a_util->diff, b_util->diff);
			else
				c = COST_MAX;
			cost[i + n * j] = c;
		}

		c = a_util->matching < 0 ?
			a_util->diffsize * creation_factor / 100 : COST_MAX;
		for (j = b->nr; j < n; j++)
			cost[i + n * j] = c;
	}

	for (j = 0; j < b->nr; j++) {
		struct patch_util *util = b->items[j].util;

		c = util->matching < 0 ?
			util->diffsize * creation_factor / 100 : COST_MAX;
		for (i = a->nr; i < n; i++)
			cost[i + n * j] = c;
	}

	for (i = a->nr; i < n; i++)
		for (j = b->nr; j < n; j++)
			cost[i + n * j] = 0;

	compute_assignment(n, n, cost, a2b, b2a);

	for (i = 0; i < a->nr; i++)
		if (a2b[i] >= 0 && a2b[i] < b->nr) {
			struct patch_util *a_util = a->items[i].util;
			struct patch_util *b_util = b->items[a2b[i]].util;

			a_util->matching = a2b[i];
			b_util->matching = i;
		}

	free(cost);
	free(a2b);
	free(b2a);
}

static void output_pair_header(struct diff_options *diffopt,
			       int patch_no_width,
			       struct strbuf *buf,
			       struct strbuf *dashes,
			       struct patch_util *a_util,
			       struct patch_util *b_util)
{
	struct object_id *oid = a_util ? &a_util->oid : &b_util->oid;
	struct commit *commit;
	char status;
	const char *color_reset = diff_get_color_opt(diffopt, DIFF_RESET);
	const char *color_old = diff_get_color_opt(diffopt, DIFF_FILE_OLD);
	const char *color_new = diff_get_color_opt(diffopt, DIFF_FILE_NEW);
	const char *color_commit = diff_get_color_opt(diffopt, DIFF_COMMIT);
	const char *color;

	if (!dashes->len)
		strbuf_addchars(dashes, '-',
				strlen(find_unique_abbrev(oid,
							  DEFAULT_ABBREV)));

	if (!b_util) {
		color = color_old;
		status = '<';
	} else if (!a_util) {
		color = color_new;
		status = '>';
	} else if (strcmp(a_util->patch, b_util->patch)) {
		color = color_commit;
		status = '!';
	} else {
		color = color_commit;
		status = '=';
	}

	strbuf_reset(buf);
	strbuf_addstr(buf, status == '!' ? color_old : color);
	if (!a_util)
		strbuf_addf(buf, "%*s:  %s ", patch_no_width, "-", dashes->buf);
	else
		strbuf_addf(buf, "%*d:  %s ", patch_no_width, a_util->i + 1,
			    find_unique_abbrev(&a_util->oid, DEFAULT_ABBREV));

	if (status == '!')
		strbuf_addf(buf, "%s%s", color_reset, color);
	strbuf_addch(buf, status);
	if (status == '!')
		strbuf_addf(buf, "%s%s", color_reset, color_new);

	if (!b_util)
		strbuf_addf(buf, " %*s:  %s", patch_no_width, "-", dashes->buf);
	else
		strbuf_addf(buf, " %*d:  %s", patch_no_width, b_util->i + 1,
			    find_unique_abbrev(&b_util->oid, DEFAULT_ABBREV));

	commit = lookup_commit_reference(the_repository, oid);
	if (commit) {
		if (status == '!')
			strbuf_addf(buf, "%s%s", color_reset, color);

		strbuf_addch(buf, ' ');
		pp_commit_easy(CMIT_FMT_ONELINE, commit, buf);
	}
	strbuf_addf(buf, "%s\n", color_reset);

	fwrite(buf->buf, buf->len, 1, diffopt->file);
}

static struct userdiff_driver section_headers = {
	.funcname = { "^ ## (.*) ##$\n"
		      "^.?@@ (.*)$", REG_EXTENDED }
};

static struct diff_filespec *get_filespec(const char *name, const char *p)
{
	struct diff_filespec *spec = alloc_filespec(name);

	fill_filespec(spec, &null_oid, 0, 0100644);
	spec->data = (char *)p;
	spec->size = strlen(p);
	spec->should_munmap = 0;
	spec->is_stdin = 1;
	spec->driver = &section_headers;

	return spec;
}

static void patch_diff(const char *a, const char *b,
		       struct diff_options *diffopt)
{
	diff_queue(&diff_queued_diff,
		   get_filespec("a", a), get_filespec("b", b));

	diffcore_std(diffopt);
	diff_flush(diffopt);
}

static struct strbuf *output_prefix_cb(struct diff_options *opt, void *data)
{
	return data;
}

static void output(struct string_list *a, struct string_list *b,
		   struct range_diff_options *range_diff_opts)
{
	struct strbuf buf = STRBUF_INIT, dashes = STRBUF_INIT;
	int patch_no_width = decimal_width(1 + (a->nr > b->nr ? a->nr : b->nr));
	int i = 0, j = 0;
	struct diff_options opts;
	struct strbuf indent = STRBUF_INIT;

	if (range_diff_opts->diffopt)
		memcpy(&opts, range_diff_opts->diffopt, sizeof(opts));
	else
		diff_setup(&opts);

	if (!opts.output_format)
		opts.output_format = DIFF_FORMAT_PATCH;
	opts.flags.suppress_diff_headers = 1;
	opts.flags.dual_color_diffed_diffs =
		range_diff_opts->dual_color;
	opts.flags.suppress_hunk_header_line_count = 1;
	opts.output_prefix = output_prefix_cb;
	strbuf_addstr(&indent, "    ");
	opts.output_prefix_data = &indent;
	diff_setup_done(&opts);

	/*
	 * We assume the user is really more interested in the second argument
	 * ("newer" version). To that end, we print the output in the order of
	 * the RHS (the `b` parameter). To put the LHS (the `a` parameter)
	 * commits that are no longer in the RHS into a good place, we place
	 * them once we have shown all of their predecessors in the LHS.
	 */

	while (i < a->nr || j < b->nr) {
		struct patch_util *a_util, *b_util;
		a_util = i < a->nr ? a->items[i].util : NULL;
		b_util = j < b->nr ? b->items[j].util : NULL;

		/* Skip all the already-shown commits from the LHS. */
		while (i < a->nr && a_util->shown)
			a_util = ++i < a->nr ? a->items[i].util : NULL;

		/* Show unmatched LHS commit whose predecessors were shown. */
		if (i < a->nr && a_util->matching < 0) {
			output_pair_header(&opts, patch_no_width,
					   &buf, &dashes, a_util, NULL);
			i++;
			continue;
		}

		/* Show unmatched RHS commits. */
		while (j < b->nr && b_util->matching < 0) {
			output_pair_header(&opts, patch_no_width,
					   &buf, &dashes, NULL, b_util);
			b_util = ++j < b->nr ? b->items[j].util : NULL;
		}

		/* Show matching LHS/RHS pair. */
		if (j < b->nr) {
			a_util = a->items[b_util->matching].util;
			output_pair_header(&opts, patch_no_width,
					   &buf, &dashes, a_util, b_util);
			if (!(opts.output_format & DIFF_FORMAT_NO_OUTPUT))
				patch_diff(a->items[b_util->matching].string,
					   b->items[j].string, &opts);
			a_util->shown = 1;
			j++;
		}
	}
	strbuf_release(&buf);
	strbuf_release(&dashes);
	strbuf_release(&indent);
}

int show_range_diff(const char *range1, const char *range2,
		    struct range_diff_options *range_diff_opts)
{
	int res = 0;

	struct string_list branch1 = STRING_LIST_INIT_DUP;
	struct string_list branch2 = STRING_LIST_INIT_DUP;

	if (read_patches(range1, &branch1, range_diff_opts->other_arg))
		res = error(_("could not parse log for '%s'"), range1);
	if (!res && read_patches(range2, &branch2, range_diff_opts->other_arg))
		res = error(_("could not parse log for '%s'"), range2);

	if (!res) {
		find_exact_matches(&branch1, &branch2);
		get_correspondences(&branch1, &branch2,
				    range_diff_opts->creation_factor);
		output(&branch1, &branch2, range_diff_opts);
	}

	string_list_clear(&branch1, 1);
	string_list_clear(&branch2, 1);

	return res;
}
Commit	Line	Data
d9c66f0b JS	1	#include "cache.h"
	2	#include "range-diff.h"
	3	#include "string-list.h"
	4	#include "run-command.h"
dbbcd44f	5	#include "strvec.h"
d9c66f0b JS	6	#include "hashmap.h"
	7	#include "xdiff-interface.h"
	8	#include "linear-assignment.h"
c8c5e43a	9	#include "diffcore.h"
eb0be38c JS	10	#include "commit.h"
eb0be38c JS	11	#include "pretty.h"
4eba1fe6	12	#include "userdiff.h"
b66885a3	13	#include "apply.h"
d9c66f0b JS	14
	15	struct patch_util {
	16	/* For the search for an exact match */
	17	struct hashmap_entry e;
	18	const char diff, patch;
	19
9dc46e02	20	int i, shown;
d9c66f0b JS	21	int diffsize;
	22	size_t diff_offset;
	23	/* the index of the matching item in the other branch, or -1 */
	24	int matching;
	25	struct object_id oid;
	26	};
	27
44b67cb6 TG	28	static size_t find_end_of_line(char *buffer, unsigned long size)
	29	{
	30	char *eol = memchr(buffer, '\n', size);
	31
	32	if (!eol)
	33	return size;
	34
	35	*eol = '\0';
	36	return eol + 1 - buffer;
	37	}
	38
d9c66f0b JS	39	/*
	40	* Reads the patches into a string list, with the `util` field being populated
	41	* as struct object_id (will need to be free()d).
	42	*/
bd361918	43	static int read_patches(const char range, struct string_list list,
c972bf4c	44	const struct strvec *other_arg)
d9c66f0b JS	45	{
d9c66f0b JS	46	struct child_process cp = CHILD_PROCESS_INIT;
44b67cb6	47	struct strbuf buf = STRBUF_INIT, contents = STRBUF_INIT;
d9c66f0b JS	48	struct patch_util *util = NULL;
d9c66f0b JS	49	int in_header = 1;
444e0969	50	char line, current_filename = NULL;
44b67cb6 TG	51	int offset, len;
44b67cb6 TG	52	size_t size;
d9c66f0b	53
c972bf4c	54	strvec_pushl(&cp.args, "log", "--no-color", "-p", "--no-merges",
f6d8942b JK	55	"--reverse", "--date-order", "--decorate=no",
	56	"--no-prefix",
	57	/*
	58	* Choose indicators that are not used anywhere
	59	* else in diffs, but still look reasonable
	60	* (e.g. will not be confusing when debugging)
	61	*/
	62	"--output-indicator-new=>",
	63	"--output-indicator-old=<",
	64	"--output-indicator-context=#",
	65	"--no-abbrev-commit",
	66	"--pretty=medium",
	67	"--notes",
	68	NULL);
bd361918	69	if (other_arg)
d70a9eb6	70	strvec_pushv(&cp.args, other_arg->v);
c972bf4c	71	strvec_push(&cp.args, range);
d9c66f0b JS	72	cp.out = -1;
	73	cp.no_stdin = 1;
	74	cp.git_cmd = 1;
	75
	76	if (start_command(&cp))
	77	return error_errno(_("could not start `log`"));
44b67cb6	78	if (strbuf_read(&contents, cp.out, 0) < 0) {
d9c66f0b JS	79	error_errno(_("could not read `log` output"));
	80	finish_command(&cp);
	81	return -1;
	82	}
5189bb87 JS	83	if (finish_command(&cp))
5189bb87 JS	84	return -1;
d9c66f0b	85
44b67cb6 TG	86	line = contents.buf;
	87	size = contents.len;
	88	for (offset = 0; size > 0; offset += len, size -= len, line += len) {
d9c66f0b JS	89	const char *p;
d9c66f0b JS	90
44b67cb6 TG	91	len = find_end_of_line(line, size);
	92	line[len - 1] = '\0';
	93	if (skip_prefix(line, "commit ", &p)) {
d9c66f0b JS	94	if (util) {
	95	string_list_append(list, buf.buf)->util = util;
	96	strbuf_reset(&buf);
	97	}
	98	util = xcalloc(sizeof(*util), 1);
	99	if (get_oid(p, &util->oid)) {
	100	error(_("could not parse commit '%s'"), p);
	101	free(util);
8c29b497	102	free(current_filename);
d9c66f0b JS	103	string_list_clear(list, 1);
d9c66f0b JS	104	strbuf_release(&buf);
44b67cb6	105	strbuf_release(&contents);
d9c66f0b JS	106	return -1;
	107	}
	108	util->matching = -1;
	109	in_header = 1;
	110	continue;
	111	}
	112
8cf51561 VD	113	if (!util) {
	114	error(_("could not parse first line of `log` output: "
	115	"did not start with 'commit ': '%s'"),
	116	line);
8c29b497	117	free(current_filename);
8cf51561 VD	118	string_list_clear(list, 1);
	119	strbuf_release(&buf);
	120	strbuf_release(&contents);
8cf51561 VD	121	return -1;
	122	}
	123
44b67cb6	124	if (starts_with(line, "diff --git")) {
b66885a3 TG	125	struct patch patch = { 0 };
	126	struct strbuf root = STRBUF_INIT;
	127	int linenr = 0;
8d1675eb	128	int orig_len;
b66885a3	129
d9c66f0b JS	130	in_header = 0;
	131	strbuf_addch(&buf, '\n');
	132	if (!util->diff_offset)
	133	util->diff_offset = buf.len;
b66885a3	134	line[len - 1] = '\n';
8d1675eb	135	orig_len = len;
937b76ed	136	len = parse_git_diff_header(&root, &linenr, 0, line,
b66885a3	137	len, size, &patch);
a2d474ad JS	138	if (len < 0) {
	139	error(_("could not parse git header '%.*s'"),
	140	orig_len, line);
	141	free(util);
	142	free(current_filename);
	143	string_list_clear(list, 1);
	144	strbuf_release(&buf);
	145	strbuf_release(&contents);
	146	return -1;
	147	}
b66885a3 TG	148	strbuf_addstr(&buf, " ## ");
	149	if (patch.is_new > 0)
	150	strbuf_addf(&buf, "%s (new)", patch.new_name);
	151	else if (patch.is_delete > 0)
	152	strbuf_addf(&buf, "%s (deleted)", patch.old_name);
	153	else if (patch.is_rename)
	154	strbuf_addf(&buf, "%s => %s", patch.old_name, patch.new_name);
	155	else
	156	strbuf_addstr(&buf, patch.new_name);
	157
444e0969 TG	158	free(current_filename);
	159	if (patch.is_delete > 0)
	160	current_filename = xstrdup(patch.old_name);
	161	else
	162	current_filename = xstrdup(patch.new_name);
	163
b66885a3 TG	164	if (patch.new_mode && patch.old_mode &&
	165	patch.old_mode != patch.new_mode)
	166	strbuf_addf(&buf, " (mode change %06o => %06o)",
	167	patch.old_mode, patch.new_mode);
	168
	169	strbuf_addstr(&buf, " ##");
d9c66f0b	170	} else if (in_header) {
44b67cb6	171	if (starts_with(line, "Author: ")) {
499352c2	172	strbuf_addstr(&buf, " ## Metadata ##\n");
44b67cb6	173	strbuf_addstr(&buf, line);
d9c66f0b	174	strbuf_addstr(&buf, "\n\n");
499352c2	175	strbuf_addstr(&buf, " ## Commit message ##\n");
9f726e1b DL	176	} else if (starts_with(line, "Notes") &&
	177	line[strlen(line) - 1] == ':') {
	178	strbuf_addstr(&buf, "\n\n");
	179	/* strip the trailing colon */
	180	strbuf_addf(&buf, " ## %.*s ##\n",
	181	(int)(strlen(line) - 1), line);
44b67cb6 TG	182	} else if (starts_with(line, " ")) {
	183	p = line + len - 2;
	184	while (isspace(*p) && p >= line)
	185	p--;
	186	strbuf_add(&buf, line, p - line + 1);
d9c66f0b JS	187	strbuf_addch(&buf, '\n');
	188	}
	189	continue;
e1db2630 TG	190	} else if (skip_prefix(line, "@@ ", &p)) {
e1db2630 TG	191	p = strstr(p, "@@");
444e0969 TG	192	strbuf_addstr(&buf, "@@");
	193	if (current_filename && p[2])
	194	strbuf_addf(&buf, " %s:", current_filename);
	195	if (p)
	196	strbuf_addstr(&buf, p + 2);
b66885a3	197	} else if (!line[0])
d9c66f0b JS	198	/*
	199	* A completely blank (not ' \n', which is context)
	200	* line is not valid in a diff. We skip it
	201	* silently, because this neatly handles the blank
	202	* separator line between commits in git-log
	203	* output.
d9c66f0b JS	204	*/
d9c66f0b JS	205	continue;
44b67cb6	206	else if (line[0] == '>') {
8d5ccb59	207	strbuf_addch(&buf, '+');
44b67cb6 TG	208	strbuf_addstr(&buf, line + 1);
44b67cb6 TG	209	} else if (line[0] == '<') {
8d5ccb59	210	strbuf_addch(&buf, '-');
44b67cb6 TG	211	strbuf_addstr(&buf, line + 1);
44b67cb6 TG	212	} else if (line[0] == '#') {
8d5ccb59	213	strbuf_addch(&buf, ' ');
44b67cb6	214	strbuf_addstr(&buf, line + 1);
8d5ccb59	215	} else {
2543a641	216	strbuf_addch(&buf, ' ');
44b67cb6	217	strbuf_addstr(&buf, line);
8d5ccb59	218	}
d9c66f0b JS	219
	220	strbuf_addch(&buf, '\n');
	221	util->diffsize++;
	222	}
44b67cb6	223	strbuf_release(&contents);
d9c66f0b JS	224
	225	if (util)
	226	string_list_append(list, buf.buf)->util = util;
	227	strbuf_release(&buf);
444e0969	228	free(current_filename);
d9c66f0b	229
d9c66f0b JS	230	return 0;
	231	}
	232
	233	static int patch_util_cmp(const void dummy, const struct patch_util a,
1ca69225	234	const struct patch_util b, const char keydata)
d9c66f0b JS	235	{
	236	return strcmp(a->diff, keydata ? keydata : b->diff);
	237	}
	238
	239	static void find_exact_matches(struct string_list a, struct string_list b)
	240	{
b19315d8	241	struct hashmap map = HASHMAP_INIT((hashmap_cmp_fn)patch_util_cmp, NULL);
d9c66f0b JS	242	int i;
d9c66f0b JS	243
d9c66f0b JS	244	/* First, add the patches of a to a hash map */
	245	for (i = 0; i < a->nr; i++) {
	246	struct patch_util *util = a->items[i].util;
	247
	248	util->i = i;
	249	util->patch = a->items[i].string;
	250	util->diff = util->patch + util->diff_offset;
d22245a2	251	hashmap_entry_init(&util->e, strhash(util->diff));
b94e5c1d	252	hashmap_add(&map, &util->e);
d9c66f0b JS	253	}
	254
	255	/* Now try to find exact matches in b */
	256	for (i = 0; i < b->nr; i++) {
	257	struct patch_util util = b->items[i].util, other;
	258
	259	util->i = i;
	260	util->patch = b->items[i].string;
	261	util->diff = util->patch + util->diff_offset;
d22245a2	262	hashmap_entry_init(&util->e, strhash(util->diff));
404ab78e	263	other = hashmap_remove_entry(&map, util, e, NULL);
d9c66f0b JS	264	if (other) {
	265	if (other->matching >= 0)
	266	BUG("already assigned!");
	267
	268	other->matching = i;
	269	util->matching = other->i;
	270	}
	271	}
	272
6da1a258	273	hashmap_clear(&map);
d9c66f0b JS	274	}
	275
	276	static void diffsize_consume(void data, char line, unsigned long len)
	277	{
	278	((int )data)++;
	279	}
	280
d2eb8093 JK	281	static void diffsize_hunk(void *data, long ob, long on, long nb, long nn,
	282	const char *funcline, long funclen)
	283	{
	284	diffsize_consume(data, NULL, 0);
	285	}
	286
d9c66f0b JS	287	static int diffsize(const char a, const char b)
	288	{
	289	xpparam_t pp = { 0 };
	290	xdemitconf_t cfg = { 0 };
	291	mmfile_t mf1, mf2;
	292	int count = 0;
	293
	294	mf1.ptr = (char *)a;
	295	mf1.size = strlen(a);
	296	mf2.ptr = (char *)b;
	297	mf2.size = strlen(b);
	298
	299	cfg.ctxlen = 3;
d2eb8093 JK	300	if (!xdi_diff_outf(&mf1, &mf2,
	301	diffsize_hunk, diffsize_consume, &count,
	302	&pp, &cfg))
d9c66f0b JS	303	return count;
	304
	305	error(_("failed to generate diff"));
	306	return COST_MAX;
	307	}
	308
	309	static void get_correspondences(struct string_list a, struct string_list b,
	310	int creation_factor)
	311	{
	312	int n = a->nr + b->nr;
	313	int cost, c, a2b, *b2a;
	314	int i, j;
	315
	316	ALLOC_ARRAY(cost, st_mult(n, n));
	317	ALLOC_ARRAY(a2b, n);
	318	ALLOC_ARRAY(b2a, n);
	319
	320	for (i = 0; i < a->nr; i++) {
	321	struct patch_util *a_util = a->items[i].util;
	322
	323	for (j = 0; j < b->nr; j++) {
	324	struct patch_util *b_util = b->items[j].util;
	325
	326	if (a_util->matching == j)
	327	c = 0;
	328	else if (a_util->matching < 0 && b_util->matching < 0)
	329	c = diffsize(a_util->diff, b_util->diff);
	330	else
	331	c = COST_MAX;
	332	cost[i + n * j] = c;
	333	}
	334
	335	c = a_util->matching < 0 ?
	336	a_util->diffsize * creation_factor / 100 : COST_MAX;
	337	for (j = b->nr; j < n; j++)
	338	cost[i + n * j] = c;
	339	}
	340
	341	for (j = 0; j < b->nr; j++) {
	342	struct patch_util *util = b->items[j].util;
	343
	344	c = util->matching < 0 ?
	345	util->diffsize * creation_factor / 100 : COST_MAX;
	346	for (i = a->nr; i < n; i++)
	347	cost[i + n * j] = c;
	348	}
	349
	350	for (i = a->nr; i < n; i++)
	351	for (j = b->nr; j < n; j++)
	352	cost[i + n * j] = 0;
	353
	354	compute_assignment(n, n, cost, a2b, b2a);
	355
	356	for (i = 0; i < a->nr; i++)
	357	if (a2b[i] >= 0 && a2b[i] < b->nr) {
	358	struct patch_util *a_util = a->items[i].util;
	359	struct patch_util *b_util = b->items[a2b[i]].util;
	360
	361	a_util->matching = a2b[i];
	362	b_util->matching = i;
	363	}
	364
	365	free(cost);
	366	free(a2b);
367	free(b2a);
368	}
369
faa1df86	370	static void output_pair_header(struct diff_options *diffopt,
d1f87a2d	371	int patch_no_width,
faa1df86	372	struct strbuf *buf,
eb0be38c JS	373	struct strbuf *dashes,
	374	struct patch_util *a_util,
	375	struct patch_util *b_util)
d9c66f0b	376	{
eb0be38c JS	377	struct object_id *oid = a_util ? &a_util->oid : &b_util->oid;
eb0be38c JS	378	struct commit *commit;
faa1df86 JS	379	char status;
	380	const char *color_reset = diff_get_color_opt(diffopt, DIFF_RESET);
	381	const char *color_old = diff_get_color_opt(diffopt, DIFF_FILE_OLD);
	382	const char *color_new = diff_get_color_opt(diffopt, DIFF_FILE_NEW);
	383	const char *color_commit = diff_get_color_opt(diffopt, DIFF_COMMIT);
	384	const char *color;
eb0be38c JS	385
	386	if (!dashes->len)
	387	strbuf_addchars(dashes, '-',
	388	strlen(find_unique_abbrev(oid,
	389	DEFAULT_ABBREV)));
	390
faa1df86 JS	391	if (!b_util) {
	392	color = color_old;
	393	status = '<';
	394	} else if (!a_util) {
	395	color = color_new;
	396	status = '>';
	397	} else if (strcmp(a_util->patch, b_util->patch)) {
	398	color = color_commit;
	399	status = '!';
	400	} else {
	401	color = color_commit;
	402	status = '=';
	403	}
	404
eb0be38c	405	strbuf_reset(buf);
faa1df86	406	strbuf_addstr(buf, status == '!' ? color_old : color);
eb0be38c	407	if (!a_util)
d1f87a2d	408	strbuf_addf(buf, "%*s: %s ", patch_no_width, "-", dashes->buf);
eb0be38c	409	else
d1f87a2d	410	strbuf_addf(buf, "%*d: %s ", patch_no_width, a_util->i + 1,
eb0be38c JS	411	find_unique_abbrev(&a_util->oid, DEFAULT_ABBREV));
eb0be38c JS	412
faa1df86 JS	413	if (status == '!')
	414	strbuf_addf(buf, "%s%s", color_reset, color);
	415	strbuf_addch(buf, status);
	416	if (status == '!')
	417	strbuf_addf(buf, "%s%s", color_reset, color_new);
eb0be38c JS	418
eb0be38c JS	419	if (!b_util)
d1f87a2d	420	strbuf_addf(buf, " %*s: %s", patch_no_width, "-", dashes->buf);
eb0be38c	421	else
d1f87a2d	422	strbuf_addf(buf, " %*d: %s", patch_no_width, b_util->i + 1,
eb0be38c JS	423	find_unique_abbrev(&b_util->oid, DEFAULT_ABBREV));
	424
	425	commit = lookup_commit_reference(the_repository, oid);
	426	if (commit) {
faa1df86 JS	427	if (status == '!')
	428	strbuf_addf(buf, "%s%s", color_reset, color);
	429
eb0be38c JS	430	strbuf_addch(buf, ' ');
	431	pp_commit_easy(CMIT_FMT_ONELINE, commit, buf);
	432	}
faa1df86	433	strbuf_addf(buf, "%s\n", color_reset);
eb0be38c	434
87f1b2d4	435	fwrite(buf->buf, buf->len, 1, diffopt->file);
d9c66f0b JS	436	}
d9c66f0b JS	437
499352c2 TG	438	static struct userdiff_driver section_headers = {
	439	.funcname = { "^ ## (.*) ##$\n"
	440	"^.?@@ (.*)$", REG_EXTENDED }
4eba1fe6 JS	441	};
4eba1fe6 JS	442
c8c5e43a JS	443	static struct diff_filespec get_filespec(const char name, const char *p)
	444	{
	445	struct diff_filespec *spec = alloc_filespec(name);
	446
0e573e8f	447	fill_filespec(spec, &null_oid, 0, 0100644);
c8c5e43a JS	448	spec->data = (char *)p;
	449	spec->size = strlen(p);
	450	spec->should_munmap = 0;
	451	spec->is_stdin = 1;
499352c2	452	spec->driver = &section_headers;
c8c5e43a JS	453
	454	return spec;
	455	}
	456
	457	static void patch_diff(const char a, const char b,
1ca69225	458	struct diff_options *diffopt)
c8c5e43a JS	459	{
	460	diff_queue(&diff_queued_diff,
	461	get_filespec("a", a), get_filespec("b", b));
	462
	463	diffcore_std(diffopt);
	464	diff_flush(diffopt);
	465	}
	466
3e6046ed JS	467	static struct strbuf output_prefix_cb(struct diff_options opt, void *data)
	468	{
	469	return data;
	470	}
	471
c8c5e43a	472	static void output(struct string_list a, struct string_list b,
3e6046ed	473	struct range_diff_options *range_diff_opts)
d9c66f0b	474	{
eb0be38c	475	struct strbuf buf = STRBUF_INIT, dashes = STRBUF_INIT;
d1f87a2d	476	int patch_no_width = decimal_width(1 + (a->nr > b->nr ? a->nr : b->nr));
9dc46e02	477	int i = 0, j = 0;
3e6046ed JS	478	struct diff_options opts;
	479	struct strbuf indent = STRBUF_INIT;
	480
	481	if (range_diff_opts->diffopt)
	482	memcpy(&opts, range_diff_opts->diffopt, sizeof(opts));
	483	else
	484	diff_setup(&opts);
	485
	486	if (!opts.output_format)
	487	opts.output_format = DIFF_FORMAT_PATCH;
	488	opts.flags.suppress_diff_headers = 1;
	489	opts.flags.dual_color_diffed_diffs =
	490	range_diff_opts->dual_color;
	491	opts.flags.suppress_hunk_header_line_count = 1;
	492	opts.output_prefix = output_prefix_cb;
	493	strbuf_addstr(&indent, " ");
	494	opts.output_prefix_data = &indent;
	495	diff_setup_done(&opts);
9dc46e02 JS	496
	497	/*
	498	* We assume the user is really more interested in the second argument
	499	* ("newer" version). To that end, we print the output in the order of
	500	* the RHS (the `b` parameter). To put the LHS (the `a` parameter)
	501	* commits that are no longer in the RHS into a good place, we place
	502	* them once we have shown all of their predecessors in the LHS.
	503	*/
	504
	505	while (i < a->nr \|\| j < b->nr) {
	506	struct patch_util a_util, b_util;
	507	a_util = i < a->nr ? a->items[i].util : NULL;
	508	b_util = j < b->nr ? b->items[j].util : NULL;
	509
	510	/* Skip all the already-shown commits from the LHS. */
	511	while (i < a->nr && a_util->shown)
	512	a_util = ++i < a->nr ? a->items[i].util : NULL;
	513
	514	/* Show unmatched LHS commit whose predecessors were shown. */
	515	if (i < a->nr && a_util->matching < 0) {
3e6046ed	516	output_pair_header(&opts, patch_no_width,
faa1df86	517	&buf, &dashes, a_util, NULL);
9dc46e02 JS	518	i++;
	519	continue;
	520	}
d9c66f0b	521
9dc46e02 JS	522	/* Show unmatched RHS commits. */
9dc46e02 JS	523	while (j < b->nr && b_util->matching < 0) {
3e6046ed	524	output_pair_header(&opts, patch_no_width,
faa1df86	525	&buf, &dashes, NULL, b_util);
9dc46e02	526	b_util = ++j < b->nr ? b->items[j].util : NULL;
d9c66f0b	527	}
d9c66f0b	528
9dc46e02 JS	529	/* Show matching LHS/RHS pair. */
	530	if (j < b->nr) {
	531	a_util = a->items[b_util->matching].util;
3e6046ed	532	output_pair_header(&opts, patch_no_width,
faa1df86	533	&buf, &dashes, a_util, b_util);
3e6046ed	534	if (!(opts.output_format & DIFF_FORMAT_NO_OUTPUT))
c8c5e43a	535	patch_diff(a->items[b_util->matching].string,
3e6046ed	536	b->items[j].string, &opts);
9dc46e02 JS	537	a_util->shown = 1;
	538	j++;
	539	}
d9c66f0b	540	}
eb0be38c JS	541	strbuf_release(&buf);
eb0be38c JS	542	strbuf_release(&dashes);
3e6046ed	543	strbuf_release(&indent);
73a834e9 ES	544	}
73a834e9 ES	545
d9c66f0b	546	int show_range_diff(const char range1, const char range2,
f1ce6c19	547	struct range_diff_options *range_diff_opts)
d9c66f0b JS	548	{
	549	int res = 0;
	550
	551	struct string_list branch1 = STRING_LIST_INIT_DUP;
	552	struct string_list branch2 = STRING_LIST_INIT_DUP;
	553
f1ce6c19	554	if (read_patches(range1, &branch1, range_diff_opts->other_arg))
d9c66f0b	555	res = error(_("could not parse log for '%s'"), range1);
f1ce6c19	556	if (!res && read_patches(range2, &branch2, range_diff_opts->other_arg))
d9c66f0b JS	557	res = error(_("could not parse log for '%s'"), range2);
	558
	559	if (!res) {
	560	find_exact_matches(&branch1, &branch2);
f1ce6c19 JS	561	get_correspondences(&branch1, &branch2,
f1ce6c19 JS	562	range_diff_opts->creation_factor);
3e6046ed	563	output(&branch1, &branch2, range_diff_opts);
d9c66f0b JS	564	}
	565
	566	string_list_clear(&branch1, 1);
	567	string_list_clear(&branch2, 1);
	568
	569	return res;
	570	}