X-Git-Url: https://git.octo.it/?a=blobdiff_plain;f=diff.c;h=e496905bad9853f912e1bbcc081c544524f8cb77;hb=53069686601d156dea3787a100ffc4e35c78040f;hp=527cbf04adf86fe6fc4c449971ac177d63736330;hpb=51017101c7a308745ba3c04944457f1dc6a55780;p=git.git

diff --git a/diff.c b/diff.c
index 527cbf04..e496905b 100644
--- a/diff.c
+++ b/diff.c
@@ -8,36 +8,70 @@
 #include "quote.h"
 #include "diff.h"
 #include "diffcore.h"
+#include "xdiff/xdiff.h"
 
-static const char *diff_opts = "-pu";
-static unsigned char null_sha1[20] = { 0, };
-
-static int reverse_diff;
 static int use_size_cache;
 
+int diff_rename_limit_default = -1;
+
+int git_diff_config(const char *var, const char *value)
+{
+	if (!strcmp(var, "diff.renamelimit")) {
+		diff_rename_limit_default = git_config_int(var, value);
+		return 0;
+	}
+
+	return git_default_config(var, value);
+}
+
+static char *quote_one(const char *str)
+{
+	int needlen;
+	char *xp;
+
+	if (!str)
+		return NULL;
+	needlen = quote_c_style(str, NULL, NULL, 0);
+	if (!needlen)
+		return strdup(str);
+	xp = xmalloc(needlen + 1);
+	quote_c_style(str, xp, NULL, 0);
+	return xp;
+}
+
+static char *quote_two(const char *one, const char *two)
+{
+	int need_one = quote_c_style(one, NULL, NULL, 1);
+	int need_two = quote_c_style(two, NULL, NULL, 1);
+	char *xp;
+
+	if (need_one + need_two) {
+		if (!need_one) need_one = strlen(one);
+		if (!need_two) need_one = strlen(two);
+
+		xp = xmalloc(need_one + need_two + 3);
+		xp[0] = '"';
+		quote_c_style(one, xp + 1, NULL, 1);
+		quote_c_style(two, xp + need_one + 1, NULL, 1);
+		strcpy(xp + need_one + need_two + 1, "\"");
+		return xp;
+	}
+	need_one = strlen(one);
+	need_two = strlen(two);
+	xp = xmalloc(need_one + need_two + 1);
+	strcpy(xp, one);
+	strcpy(xp + need_one, two);
+	return xp;
+}
+
 static const char *external_diff(void)
 {
 	static const char *external_diff_cmd = NULL;
 	static int done_preparing = 0;
-	const char *env_diff_opts;
 
 	if (done_preparing)
 		return external_diff_cmd;
-
-	/*
-	 * Default values above are meant to match the
-	 * Linux kernel development style.  Examples of
-	 * alternative styles you can specify via environment
-	 * variables are:
-	 *
-	 * GIT_DIFF_OPTS="-c";
-	 */
-	external_diff_cmd = gitenv("GIT_EXTERNAL_DIFF");
-
-	/* In case external diff fails... */
-	env_diff_opts = gitenv("GIT_DIFF_OPTS");
-	if (env_diff_opts) diff_opts = env_diff_opts;
-
+	external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 	done_preparing = 1;
 	return external_diff_cmd;
 }
@@ -51,13 +85,12 @@ static struct diff_tempfile {
 	char tmp_path[TEMPFILE_PATH_LEN];
 } diff_temp[2];
 
-static int count_lines(const char *filename)
+static int count_lines(const char *data, int size)
 {
-	FILE *in;
 	int count, ch, completely_empty = 1, nl_just_seen = 0;
-	in = fopen(filename, "r");
 	count = 0;
-	while ((ch = fgetc(in)) != EOF)
+	while (0 < size--) {
+		ch = *data++;
 		if (ch == '\n') {
 			count++;
 			nl_just_seen = 1;
@@ -67,7 +100,7 @@ static int count_lines(const char *filename)
 			nl_just_seen = 0;
 			completely_empty = 0;
 		}
-	fclose(in);
+	}
 	if (completely_empty)
 		return 0;
 	if (!nl_just_seen)
@@ -90,12 +123,11 @@ static void print_line_count(int count)
 	}
 }
 
-static void copy_file(int prefix, const char *filename)
+static void copy_file(int prefix, const char *data, int size)
 {
-	FILE *in;
 	int ch, nl_just_seen = 1;
-	in = fopen(filename, "r");
-	while ((ch = fgetc(in)) != EOF) {
+	while (0 < size--) {
+		ch = *data++;
 		if (nl_just_seen)
 			putchar(prefix);
 		putchar(ch);
@@ -104,124 +136,163 @@ static void copy_file(int prefix, const char *filename)
 		else
 			nl_just_seen = 0;
 	}
-	fclose(in);
 	if (!nl_just_seen)
 		printf("\n\\ No newline at end of file\n");
 }
 
 static void emit_rewrite_diff(const char *name_a,
 			      const char *name_b,
-			      struct diff_tempfile *temp)
+			      struct diff_filespec *one, 
+			      struct diff_filespec *two)
 {
 	/* Use temp[i].name as input, name_a and name_b as labels */
 	int lc_a, lc_b;
-	lc_a = count_lines(temp[0].name);
-	lc_b = count_lines(temp[1].name);
+	lc_a = count_lines(one->data, one->size);
+	lc_b = count_lines(two->data, two->size);
 	printf("--- %s\n+++ %s\n@@ -", name_a, name_b);
 	print_line_count(lc_a);
 	printf(" +");
 	print_line_count(lc_b);
 	printf(" @@\n");
 	if (lc_a)
-		copy_file('-', temp[0].name);
+		copy_file('-', one->data, one->size);
 	if (lc_b)
-		copy_file('+', temp[1].name);
+		copy_file('+', two->data, two->size);
 }
 
-static void builtin_diff(const char *name_a,
-			 const char *name_b,
-			 struct diff_tempfile *temp,
-			 const char *xfrm_msg,
-			 int complete_rewrite)
+static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 {
-	int i, next_at, cmd_size;
-	const char *const diff_cmd = "diff -L%s%s -L%s%s";
-	const char *const diff_arg  = "%s %s||:"; /* "||:" is to return 0 */
-	const char *input_name_sq[2];
-	const char *path0[2];
-	const char *path1[2];
-	const char *name_sq[2];
-	char *cmd;
-
-	name_sq[0] = sq_quote(name_a);
-	name_sq[1] = sq_quote(name_b);
-
-	/* diff_cmd and diff_arg have 6 %s in total which makes
-	 * the sum of these strings 12 bytes larger than required.
-	 * we use 2 spaces around diff-opts, and we need to count
-	 * terminating NUL, so we subtract 9 here.
-	 */
-	cmd_size = (strlen(diff_cmd) + strlen(diff_opts) +
-			strlen(diff_arg) - 9);
-	for (i = 0; i < 2; i++) {
-		input_name_sq[i] = sq_quote(temp[i].name);
-		if (!strcmp(temp[i].name, "/dev/null")) {
-			path0[i] = "/dev/null";
-			path1[i] = "";
-		} else {
-			path0[i] = i ? "b/" : "a/";
-			path1[i] = name_sq[i];
-		}
-		cmd_size += (strlen(path0[i]) + strlen(path1[i]) +
-			     strlen(input_name_sq[i]));
+	if (!DIFF_FILE_VALID(one)) {
+		mf->ptr = ""; /* does not matter */
+		mf->size = 0;
+		return 0;
 	}
+	else if (diff_populate_filespec(one, 0))
+		return -1;
+	mf->ptr = one->data;
+	mf->size = one->size;
+	return 0;
+}
+
+struct emit_callback {
+	const char **label_path;
+};
+
+static int fn_out(void *priv, mmbuffer_t *mb, int nbuf)
+{
+	int i;
+	struct emit_callback *ecbdata = priv;
 
-	cmd = xmalloc(cmd_size);
+	if (ecbdata->label_path[0]) {
+		printf("--- %s\n", ecbdata->label_path[0]);
+		printf("+++ %s\n", ecbdata->label_path[1]);
+		ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
+	}
+	for (i = 0; i < nbuf; i++)
+		if (!fwrite(mb[i].ptr, mb[i].size, 1, stdout))
+			return -1;
+	return 0;
+}
 
-	next_at = 0;
-	next_at += snprintf(cmd+next_at, cmd_size-next_at,
-			    diff_cmd,
-			    path0[0], path1[0], path0[1], path1[1]);
-	next_at += snprintf(cmd+next_at, cmd_size-next_at,
-			    " %s ", diff_opts);
-	next_at += snprintf(cmd+next_at, cmd_size-next_at,
-			    diff_arg, input_name_sq[0], input_name_sq[1]);
+#define FIRST_FEW_BYTES 8000
+static int mmfile_is_binary(mmfile_t *mf)
+{
+	long sz = mf->size;
+	if (FIRST_FEW_BYTES < sz)
+		sz = FIRST_FEW_BYTES;
+	if (memchr(mf->ptr, 0, sz))
+		return 1;
+	return 0;
+}
 
-	printf("diff --git a/%s b/%s\n", name_a, name_b);
-	if (!path1[0][0]) {
-		printf("new file mode %s\n", temp[1].mode);
+static void builtin_diff(const char *name_a,
+			 const char *name_b,
+			 struct diff_filespec *one,
+			 struct diff_filespec *two,
+			 const char *xfrm_msg,
+			 int complete_rewrite)
+{
+	mmfile_t mf1, mf2;
+	const char *lbl[2];
+	char *a_one, *b_two;
+
+	a_one = quote_two("a/", name_a);
+	b_two = quote_two("b/", name_b);
+	lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
+	lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
+	printf("diff --git %s %s\n", a_one, b_two);
+	if (lbl[0][0] == '/') {
+		/* /dev/null */
+		printf("new file mode %06o\n", two->mode);
 		if (xfrm_msg && xfrm_msg[0])
 			puts(xfrm_msg);
 	}
-	else if (!path1[1][0]) {
-		printf("deleted file mode %s\n", temp[0].mode);
+	else if (lbl[1][0] == '/') {
+		printf("deleted file mode %06o\n", one->mode);
 		if (xfrm_msg && xfrm_msg[0])
 			puts(xfrm_msg);
 	}
 	else {
-		if (strcmp(temp[0].mode, temp[1].mode)) {
-			printf("old mode %s\n", temp[0].mode);
-			printf("new mode %s\n", temp[1].mode);
+		if (one->mode != two->mode) {
+			printf("old mode %06o\n", one->mode);
+			printf("new mode %06o\n", two->mode);
 		}
 		if (xfrm_msg && xfrm_msg[0])
 			puts(xfrm_msg);
-		if (strncmp(temp[0].mode, temp[1].mode, 3))
-			/* we do not run diff between different kind
-			 * of objects.
-			 */
-			exit(0);
+		/*
+		 * we do not run diff between different kind
+		 * of objects.
+		 */
+		if ((one->mode ^ two->mode) & S_IFMT)
+			goto free_ab_and_return;
 		if (complete_rewrite) {
-			fflush(NULL);
-			emit_rewrite_diff(name_a, name_b, temp);
-			exit(0);
+			emit_rewrite_diff(name_a, name_b, one, two);
+			goto free_ab_and_return;
 		}
 	}
-	fflush(NULL);
-	execlp("/bin/sh","sh", "-c", cmd, NULL);
+
+	if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
+		die("unable to read files to diff");
+
+	if (mmfile_is_binary(&mf1) || mmfile_is_binary(&mf2))
+		printf("Binary files %s and %s differ\n", lbl[0], lbl[1]);
+	else {
+		/* Crazy xdl interfaces.. */
+		const char *diffopts = getenv("GIT_DIFF_OPTS");
+		xpparam_t xpp;
+		xdemitconf_t xecfg;
+		xdemitcb_t ecb;
+		struct emit_callback ecbdata;
+
+		ecbdata.label_path = lbl;
+		xpp.flags = XDF_NEED_MINIMAL;
+		xecfg.ctxlen = 3;
+		xecfg.flags = XDL_EMIT_FUNCNAMES;
+		if (!diffopts)
+			;
+		else if (!strncmp(diffopts, "--unified=", 10))
+			xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
+		else if (!strncmp(diffopts, "-u", 2))
+			xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
+		ecb.outf = fn_out;
+		ecb.priv = &ecbdata;
+		xdl_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
+	}
+
+ free_ab_and_return:
+	free(a_one);
+	free(b_two);
+	return;
 }
 
 struct diff_filespec *alloc_filespec(const char *path)
 {
 	int namelen = strlen(path);
 	struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
+
+	memset(spec, 0, sizeof(*spec));
 	spec->path = (char *)(spec + 1);
-	strcpy(spec->path, path);
-	spec->should_free = spec->should_munmap = 0;
-	spec->xfrm_flags = 0;
-	spec->size = 0;
-	spec->data = NULL;
-	spec->mode = 0;
-	memset(spec->sha1, 0, 20);
+	memcpy(spec->path, path, namelen+1);
 	return spec;
 }
 
@@ -229,7 +300,7 @@ void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
 		   unsigned short mode)
 {
 	if (mode) {
-		spec->mode = DIFF_FILE_CANON_MODE(mode);
+		spec->mode = canon_mode(mode);
 		memcpy(spec->sha1, sha1, 20);
 		spec->sha1_valid = !!memcmp(sha1, null_sha1, 20);
 	}
@@ -268,7 +339,7 @@ static int work_tree_matches(const char *name, const unsigned char *sha1)
 	ce = active_cache[pos];
 	if ((lstat(name, &st) < 0) ||
 	    !S_ISREG(st.st_mode) || /* careful! */
-	    ce_match_stat(ce, &st) ||
+	    ce_match_stat(ce, &st, 0) ||
 	    memcmp(sha1, ce->sha1, 20))
 		return 0;
 	/* we return 1 only when we can stat, it is a regular file,
@@ -406,19 +477,22 @@ int diff_populate_filespec(struct diff_filespec *s, int size_only)
 	return 0;
 }
 
-void diff_free_filespec(struct diff_filespec *s)
+void diff_free_filespec_data(struct diff_filespec *s)
 {
 	if (s->should_free)
 		free(s->data);
 	else if (s->should_munmap)
 		munmap(s->data, s->size);
-	free(s);
+	s->should_free = s->should_munmap = 0;
+	s->data = NULL;
+	free(s->cnt_data);
+	s->cnt_data = NULL;
 }
 
 static void prep_temp_blob(struct diff_tempfile *temp,
 			   void *blob,
 			   unsigned long size,
-			   unsigned char *sha1,
+			   const unsigned char *sha1,
 			   int mode)
 {
 	int fd;
@@ -460,9 +534,9 @@ static void prepare_temp_file(const char *name,
 		}
 		if (S_ISLNK(st.st_mode)) {
 			int ret;
-			char *buf, buf_[1024];
-			buf = ((sizeof(buf_) < st.st_size) ?
-			       xmalloc(st.st_size) : buf_);
+			char buf[PATH_MAX + 1]; /* ought to be SYMLINK_MAX */
+			if (sizeof(buf) <= st.st_size)
+				die("symlink too long: %s", name);
 			ret = readlink(name, buf, st.st_size);
 			if (ret < 0)
 				die("readlink(%s)", name);
@@ -511,6 +585,42 @@ static void remove_tempfile(void)
 static void remove_tempfile_on_signal(int signo)
 {
 	remove_tempfile();
+	signal(SIGINT, SIG_DFL);
+	raise(signo);
+}
+
+static int spawn_prog(const char *pgm, const char **arg)
+{
+	pid_t pid;
+	int status;
+
+	fflush(NULL);
+	pid = fork();
+	if (pid < 0)
+		die("unable to fork");
+	if (!pid) {
+		execvp(pgm, (char *const*) arg);
+		exit(255);
+	}
+
+	while (waitpid(pid, &status, 0) < 0) {
+		if (errno == EINTR)
+			continue;
+		return -1;
+	}
+
+	/* Earlier we did not check the exit status because
+	 * diff exits non-zero if files are different, and
+	 * we are not interested in knowing that.  It was a
+	 * mistake which made it harder to quit a diff-*
+	 * session that uses the git-apply-patch-script as
+	 * the GIT_EXTERNAL_DIFF.  A custom GIT_EXTERNAL_DIFF
+	 * should also exit non-zero only when it wants to
+	 * abort the entire diff-* session.
+	 */
+	if (WIFEXITED(status) && !WEXITSTATUS(status))
+		return 0;
+	return -1;
 }
 
 /* An external diff command takes:
@@ -527,11 +637,12 @@ static void run_external_diff(const char *pgm,
 			      const char *xfrm_msg,
 			      int complete_rewrite)
 {
+	const char *spawn_arg[10];
 	struct diff_tempfile *temp = diff_temp;
-	pid_t pid;
-	int status;
+	int retval;
 	static int atexit_asked = 0;
 	const char *othername;
+	const char **arg = &spawn_arg[0];
 
 	othername = (other? other : name);
 	if (one && two) {
@@ -546,114 +657,146 @@ static void run_external_diff(const char *pgm,
 		signal(SIGINT, remove_tempfile_on_signal);
 	}
 
-	fflush(NULL);
-	pid = fork();
-	if (pid < 0)
-		die("unable to fork");
-	if (!pid) {
-		if (pgm) {
-			if (one && two) {
-				const char *exec_arg[10];
-				const char **arg = &exec_arg[0];
-				*arg++ = pgm;
-				*arg++ = name;
-				*arg++ = temp[0].name;
-				*arg++ = temp[0].hex;
-				*arg++ = temp[0].mode;
-				*arg++ = temp[1].name;
-				*arg++ = temp[1].hex;
-				*arg++ = temp[1].mode;
-				if (other) {
-					*arg++ = other;
-					*arg++ = xfrm_msg;
-				}
-				*arg = NULL;
-				execvp(pgm, (char *const*) exec_arg);
-			}
-			else
-				execlp(pgm, pgm, name, NULL);
+	if (one && two) {
+		*arg++ = pgm;
+		*arg++ = name;
+		*arg++ = temp[0].name;
+		*arg++ = temp[0].hex;
+		*arg++ = temp[0].mode;
+		*arg++ = temp[1].name;
+		*arg++ = temp[1].hex;
+		*arg++ = temp[1].mode;
+		if (other) {
+			*arg++ = other;
+			*arg++ = xfrm_msg;
 		}
-		/*
-		 * otherwise we use the built-in one.
-		 */
-		if (one && two)
-			builtin_diff(name, othername, temp, xfrm_msg,
-				     complete_rewrite);
-		else
-			printf("* Unmerged path %s\n", name);
-		exit(0);
+	} else {
+		*arg++ = pgm;
+		*arg++ = name;
 	}
-	if (waitpid(pid, &status, 0) < 0 ||
-	    !WIFEXITED(status) || WEXITSTATUS(status)) {
-		/* Earlier we did not check the exit status because
-		 * diff exits non-zero if files are different, and
-		 * we are not interested in knowing that.  It was a
-		 * mistake which made it harder to quit a diff-*
-		 * session that uses the git-apply-patch-script as
-		 * the GIT_EXTERNAL_DIFF.  A custom GIT_EXTERNAL_DIFF
-		 * should also exit non-zero only when it wants to
-		 * abort the entire diff-* session.
-		 */
-		remove_tempfile();
+	*arg = NULL;
+	retval = spawn_prog(pgm, spawn_arg);
+	remove_tempfile();
+	if (retval) {
 		fprintf(stderr, "external diff died, stopping at %s.\n", name);
 		exit(1);
 	}
-	remove_tempfile();
 }
 
-static void run_diff(struct diff_filepair *p)
+static void run_diff_cmd(const char *pgm,
+			 const char *name,
+			 const char *other,
+			 struct diff_filespec *one,
+			 struct diff_filespec *two,
+			 const char *xfrm_msg,
+			 int complete_rewrite)
+{
+	if (pgm) {
+		run_external_diff(pgm, name, other, one, two, xfrm_msg,
+				  complete_rewrite);
+		return;
+	}
+	if (one && two)
+		builtin_diff(name, other ? other : name,
+			     one, two, xfrm_msg, complete_rewrite);
+	else
+		printf("* Unmerged path %s\n", name);
+}
+
+static void diff_fill_sha1_info(struct diff_filespec *one)
+{
+	if (DIFF_FILE_VALID(one)) {
+		if (!one->sha1_valid) {
+			struct stat st;
+			if (lstat(one->path, &st) < 0)
+				die("stat %s", one->path);
+			if (index_path(one->sha1, one->path, &st, 0))
+				die("cannot hash %s\n", one->path);
+		}
+	}
+	else
+		memset(one->sha1, 0, 20);
+}
+
+static void run_diff(struct diff_filepair *p, struct diff_options *o)
 {
 	const char *pgm = external_diff();
-	char msg_[PATH_MAX*2+200], *xfrm_msg;
+	char msg[PATH_MAX*2+300], *xfrm_msg;
 	struct diff_filespec *one;
 	struct diff_filespec *two;
 	const char *name;
 	const char *other;
+	char *name_munged, *other_munged;
 	int complete_rewrite = 0;
+	int len;
 
 	if (DIFF_PAIR_UNMERGED(p)) {
 		/* unmerged */
-		run_external_diff(pgm, p->one->path, NULL, NULL, NULL, NULL,
-				  0);
+		run_diff_cmd(pgm, p->one->path, NULL, NULL, NULL, NULL, 0);
 		return;
 	}
 
 	name = p->one->path;
 	other = (strcmp(name, p->two->path) ? p->two->path : NULL);
+	name_munged = quote_one(name);
+	other_munged = quote_one(other);
 	one = p->one; two = p->two;
+
+	diff_fill_sha1_info(one);
+	diff_fill_sha1_info(two);
+
+	len = 0;
 	switch (p->status) {
 	case DIFF_STATUS_COPIED:
-		sprintf(msg_,
-			"similarity index %d%%\n"
-			"copy from %s\n"
-			"copy to %s",
-			(int)(0.5 + p->score * 100.0/MAX_SCORE),
-			name, other);
-		xfrm_msg = msg_;
+		len += snprintf(msg + len, sizeof(msg) - len,
+				"similarity index %d%%\n"
+				"copy from %s\n"
+				"copy to %s\n",
+				(int)(0.5 + p->score * 100.0/MAX_SCORE),
+				name_munged, other_munged);
 		break;
 	case DIFF_STATUS_RENAMED:
-		sprintf(msg_,
-			"similarity index %d%%\n"
-			"rename from %s\n"
-			"rename to %s",
-			(int)(0.5 + p->score * 100.0/MAX_SCORE),
-			name, other);
-		xfrm_msg = msg_;
+		len += snprintf(msg + len, sizeof(msg) - len,
+				"similarity index %d%%\n"
+				"rename from %s\n"
+				"rename to %s\n",
+				(int)(0.5 + p->score * 100.0/MAX_SCORE),
+				name_munged, other_munged);
 		break;
 	case DIFF_STATUS_MODIFIED:
 		if (p->score) {
-			sprintf(msg_,
-				"dissimilarity index %d%%",
-				(int)(0.5 + p->score * 100.0/MAX_SCORE));
-			xfrm_msg = msg_;
+			len += snprintf(msg + len, sizeof(msg) - len,
+					"dissimilarity index %d%%\n",
+					(int)(0.5 + p->score *
+					      100.0/MAX_SCORE));
 			complete_rewrite = 1;
 			break;
 		}
 		/* fallthru */
 	default:
-		xfrm_msg = NULL;
+		/* nothing */
+		;
+	}
+
+	if (memcmp(one->sha1, two->sha1, 20)) {
+		char one_sha1[41];
+		int abbrev = o->full_index ? 40 : DEFAULT_ABBREV;
+		memcpy(one_sha1, sha1_to_hex(one->sha1), 41);
+
+		len += snprintf(msg + len, sizeof(msg) - len,
+				"index %.*s..%.*s",
+				abbrev, one_sha1, abbrev,
+				sha1_to_hex(two->sha1));
+		if (one->mode == two->mode)
+			len += snprintf(msg + len, sizeof(msg) - len,
+					" %06o", one->mode);
+		len += snprintf(msg + len, sizeof(msg) - len, "\n");
 	}
 
+	if (len)
+		msg[--len] = 0;
+	xfrm_msg = len ? msg : NULL;
+
 	if (!pgm &&
 	    DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
 	    (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
@@ -661,48 +804,143 @@ static void run_diff(struct diff_filepair *p)
 		 * needs to be split into deletion and creation.
 		 */
 		struct diff_filespec *null = alloc_filespec(two->path);
-		run_external_diff(NULL, name, other, one, null, xfrm_msg, 0);
+		run_diff_cmd(NULL, name, other, one, null, xfrm_msg, 0);
 		free(null);
 		null = alloc_filespec(one->path);
-		run_external_diff(NULL, name, other, null, two, xfrm_msg, 0);
+		run_diff_cmd(NULL, name, other, null, two, xfrm_msg, 0);
 		free(null);
 	}
 	else
-		run_external_diff(pgm, name, other, one, two, xfrm_msg,
-				  complete_rewrite);
+		run_diff_cmd(pgm, name, other, one, two, xfrm_msg,
+			     complete_rewrite);
+
+	free(name_munged);
+	free(other_munged);
+}
+
+void diff_setup(struct diff_options *options)
+{
+	memset(options, 0, sizeof(*options));
+	options->output_format = DIFF_FORMAT_RAW;
+	options->line_termination = '\n';
+	options->break_opt = -1;
+	options->rename_limit = -1;
+
+	options->change = diff_change;
+	options->add_remove = diff_addremove;
 }
 
-void diff_setup(int flags)
+int diff_setup_done(struct diff_options *options)
 {
-	if (flags & DIFF_SETUP_REVERSE)
-		reverse_diff = 1;
-	if (flags & DIFF_SETUP_USE_CACHE) {
+	if ((options->find_copies_harder &&
+	     options->detect_rename != DIFF_DETECT_COPY) ||
+	    (0 <= options->rename_limit && !options->detect_rename))
+		return -1;
+	if (options->detect_rename && options->rename_limit < 0)
+		options->rename_limit = diff_rename_limit_default;
+	if (options->setup & DIFF_SETUP_USE_CACHE) {
 		if (!active_cache)
 			/* read-cache does not die even when it fails
 			 * so it is safe for us to do this here.  Also
 			 * it does not smudge active_cache or active_nr
 			 * when it fails, so we do not have to worry about
-			 * cleaning it up oufselves either.
+			 * cleaning it up ourselves either.
 			 */
 			read_cache();
 	}
-	if (flags & DIFF_SETUP_USE_SIZE_CACHE)
+	if (options->setup & DIFF_SETUP_USE_SIZE_CACHE)
 		use_size_cache = 1;
-	
+	if (options->abbrev <= 0 || 40 < options->abbrev)
+		options->abbrev = 40; /* full */
+
+	return 0;
+}
+
+int diff_opt_parse(struct diff_options *options, const char **av, int ac)
+{
+	const char *arg = av[0];
+	if (!strcmp(arg, "-p") || !strcmp(arg, "-u"))
+		options->output_format = DIFF_FORMAT_PATCH;
+	else if (!strcmp(arg, "-z"))
+		options->line_termination = 0;
+	else if (!strncmp(arg, "-l", 2))
+		options->rename_limit = strtoul(arg+2, NULL, 10);
+	else if (!strcmp(arg, "--full-index"))
+		options->full_index = 1;
+	else if (!strcmp(arg, "--name-only"))
+		options->output_format = DIFF_FORMAT_NAME;
+	else if (!strcmp(arg, "--name-status"))
+		options->output_format = DIFF_FORMAT_NAME_STATUS;
+	else if (!strcmp(arg, "-R"))
+		options->reverse_diff = 1;
+	else if (!strncmp(arg, "-S", 2))
+		options->pickaxe = arg + 2;
+	else if (!strcmp(arg, "-s"))
+		options->output_format = DIFF_FORMAT_NO_OUTPUT;
+	else if (!strncmp(arg, "-O", 2))
+		options->orderfile = arg + 2;
+	else if (!strncmp(arg, "--diff-filter=", 14))
+		options->filter = arg + 14;
+	else if (!strcmp(arg, "--pickaxe-all"))
+		options->pickaxe_opts = DIFF_PICKAXE_ALL;
+	else if (!strncmp(arg, "-B", 2)) {
+		if ((options->break_opt =
+		     diff_scoreopt_parse(arg)) == -1)
+			return -1;
+	}
+	else if (!strncmp(arg, "-M", 2)) {
+		if ((options->rename_score =
+		     diff_scoreopt_parse(arg)) == -1)
+			return -1;
+		options->detect_rename = DIFF_DETECT_RENAME;
+	}
+	else if (!strncmp(arg, "-C", 2)) {
+		if ((options->rename_score =
+		     diff_scoreopt_parse(arg)) == -1)
+			return -1;
+		options->detect_rename = DIFF_DETECT_COPY;
+	}
+	else if (!strcmp(arg, "--find-copies-harder"))
+		options->find_copies_harder = 1;
+	else if (!strcmp(arg, "--abbrev"))
+		options->abbrev = DEFAULT_ABBREV;
+	else if (!strncmp(arg, "--abbrev=", 9)) {
+		options->abbrev = strtoul(arg + 9, NULL, 10);
+		if (options->abbrev < MINIMUM_ABBREV)
+			options->abbrev = MINIMUM_ABBREV;
+		else if (40 < options->abbrev)
+			options->abbrev = 40;
+	}
+	else
+		return 0;
+	return 1;
 }
 
 static int parse_num(const char **cp_p)
 {
-	int num, scale, ch, cnt;
+	unsigned long num, scale;
+	int ch, dot;
 	const char *cp = *cp_p;
 
-	cnt = num = 0;
+	num = 0;
 	scale = 1;
-	while ('0' <= (ch = *cp) && ch <= '9') {
-		if (cnt++ < 5) {
-			/* We simply ignore more than 5 digits precision. */
-			scale *= 10;
-			num = num * 10 + ch - '0';
+	dot = 0;
+	for(;;) {
+		ch = *cp;
+		if ( !dot && ch == '.' ) {
+			scale = 1;
+			dot = 1;
+		} else if ( ch == '%' ) {
+			scale = dot ? scale*100 : 100;
+			cp++;	/* % is always at the end */
+			break;
+		} else if ( ch >= '0' && ch <= '9' ) {
+			if ( scale < 100000 ) {
+				scale *= 10;
+				num = (num*10) + (ch-'0');
+			}
+		} else {
+			break;
 		}
 		cp++;
 	}
@@ -711,7 +949,7 @@ static int parse_num(const char **cp_p)
 	/* user says num divided by scale and we say internally that
 	 * is MAX_SCORE * num / scale.
 	 */
-	return (MAX_SCORE * num / scale);
+	return (num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale);
 }
 
 int diff_scoreopt_parse(const char *opt)
@@ -765,33 +1003,61 @@ struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
 	dp->status = 0;
 	dp->source_stays = 0;
 	dp->broken_pair = 0;
-	diff_q(queue, dp);
+	if (queue)
+		diff_q(queue, dp);
 	return dp;
 }
 
 void diff_free_filepair(struct diff_filepair *p)
 {
-	diff_free_filespec(p->one);
-	diff_free_filespec(p->two);
+	diff_free_filespec_data(p->one);
+	diff_free_filespec_data(p->two);
+	free(p->one);
+	free(p->two);
 	free(p);
 }
 
+/* This is different from find_unique_abbrev() in that
+ * it stuffs the result with dots for alignment.
+ */
+const char *diff_unique_abbrev(const unsigned char *sha1, int len)
+{
+	int abblen;
+	const char *abbrev;
+	if (len == 40)
+		return sha1_to_hex(sha1);
+
+	abbrev = find_unique_abbrev(sha1, len);
+	if (!abbrev)
+		return sha1_to_hex(sha1);
+	abblen = strlen(abbrev);
+	if (abblen < 37) {
+		static char hex[41];
+		if (len < abblen && abblen <= len + 2)
+			sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
+		else
+			sprintf(hex, "%s...", abbrev);
+		return hex;
+	}
+	return sha1_to_hex(sha1);
+}
+
 static void diff_flush_raw(struct diff_filepair *p,
 			   int line_termination,
-			   int inter_name_termination)
+			   int inter_name_termination,
+			   struct diff_options *options)
 {
 	int two_paths;
 	char status[10];
+	int abbrev = options->abbrev;
+	const char *path_one, *path_two;
+	int output_format = options->output_format;
 
+	path_one = p->one->path;
+	path_two = p->two->path;
 	if (line_termination) {
-		const char *const err =
-			"path %s cannot be expressed without -z";
-		if (strchr(p->one->path, line_termination) ||
-		    strchr(p->one->path, inter_name_termination))
-			die(err, p->one->path);
-		if (strchr(p->two->path, line_termination) ||
-		    strchr(p->two->path, inter_name_termination))
-			die(err, p->two->path);
+		path_one = quote_one(path_one);
+		path_two = quote_one(path_two);
 	}
 
 	if (p->score)
@@ -814,22 +1080,36 @@ static void diff_flush_raw(struct diff_filepair *p,
 		two_paths = 0;
 		break;
 	}
-	printf(":%06o %06o %s ",
-	       p->one->mode, p->two->mode, sha1_to_hex(p->one->sha1));
-	printf("%s %s%c%s",
-	       sha1_to_hex(p->two->sha1),
-	       status,
-	       inter_name_termination,
-	       p->one->path);
+	if (output_format != DIFF_FORMAT_NAME_STATUS) {
+		printf(":%06o %06o %s ",
+		       p->one->mode, p->two->mode,
+		       diff_unique_abbrev(p->one->sha1, abbrev));
+		printf("%s ",
+		       diff_unique_abbrev(p->two->sha1, abbrev));
+	}
+	printf("%s%c%s", status, inter_name_termination, path_one);
 	if (two_paths)
-		printf("%c%s", inter_name_termination, p->two->path);
+		printf("%c%s", inter_name_termination, path_two);
 	putchar(line_termination);
+	if (path_one != p->one->path)
+		free((void*)path_one);
+	if (path_two != p->two->path)
+		free((void*)path_two);
 }
 
 static void diff_flush_name(struct diff_filepair *p,
+			    int inter_name_termination,
 			    int line_termination)
 {
-	printf("%s%c", p->two->path, line_termination);
+	char *path = p->two->path;
+
+	if (line_termination)
+		path = quote_one(p->two->path);
+	else
+		path = p->two->path;
+	printf("%s%c", path, line_termination);
+	if (p->two->path != path)
+		free(path);
 }
 
 int diff_unmodified_pair(struct diff_filepair *p)
@@ -866,7 +1146,7 @@ int diff_unmodified_pair(struct diff_filepair *p)
 	return 0;
 }
 
-static void diff_flush_patch(struct diff_filepair *p)
+static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
 {
 	if (diff_unmodified_pair(p))
 		return;
@@ -875,7 +1155,7 @@ static void diff_flush_patch(struct diff_filepair *p)
 	    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
 		return; /* no tree diffs in patch format */ 
 
-	run_diff(p);
+	run_diff(p, o);
 }
 
 int diff_queue_is_empty(void)
@@ -955,7 +1235,9 @@ static void diff_resolve_rename_copy(void)
 			}
 			/* See if there is some other filepair that
 			 * copies from the same source as us.  If so
-			 * we are a copy.  Otherwise we are a rename.
+			 * we are a copy.  Otherwise we are either a
+			 * copy if the path stays, or a rename if it
+			 * does not, but we already handled "stays" case.
 			 */
 			for (j = i + 1; j < q->nr; j++) {
 				pp = q->queue[j];
@@ -985,32 +1267,38 @@ static void diff_resolve_rename_copy(void)
 	diff_debug_queue("resolve-rename-copy done", q);
 }
 
-void diff_flush(int diff_output_style, int line_termination)
+void diff_flush(struct diff_options *options)
 {
 	struct diff_queue_struct *q = &diff_queued_diff;
 	int i;
 	int inter_name_termination = '\t';
+	int diff_output_format = options->output_format;
+	int line_termination = options->line_termination;
 
 	if (!line_termination)
 		inter_name_termination = 0;
 
 	for (i = 0; i < q->nr; i++) {
 		struct diff_filepair *p = q->queue[i];
-		if ((diff_output_style == DIFF_FORMAT_NO_OUTPUT) ||
+		if ((diff_output_format == DIFF_FORMAT_NO_OUTPUT) ||
 		    (p->status == DIFF_STATUS_UNKNOWN))
 			continue;
 		if (p->status == 0)
 			die("internal error in diff-resolve-rename-copy");
-		switch (diff_output_style) {
+		switch (diff_output_format) {
 		case DIFF_FORMAT_PATCH:
-			diff_flush_patch(p);
+			diff_flush_patch(p, options);
 			break;
 		case DIFF_FORMAT_RAW:
+		case DIFF_FORMAT_NAME_STATUS:
 			diff_flush_raw(p, line_termination,
-				       inter_name_termination);
+				       inter_name_termination,
+				       options);
 			break;
 		case DIFF_FORMAT_NAME:
-			diff_flush_name(p, line_termination);
+			diff_flush_name(p,
+					inter_name_termination,
+					line_termination);
 			break;
 		}
 		diff_free_filepair(q->queue[i]);
@@ -1076,45 +1364,36 @@ static void diffcore_apply_filter(const char *filter)
 	*q = outq;
 }
 
-void diffcore_std(const char **paths,
-		  int detect_rename, int rename_score,
-		  const char *pickaxe, int pickaxe_opts,
-		  int break_opt,
-		  const char *orderfile,
-		  const char *filter)
+void diffcore_std(struct diff_options *options)
 {
-	if (paths && paths[0])
-		diffcore_pathspec(paths);
-	if (break_opt != -1)
-		diffcore_break(break_opt);
-	if (detect_rename)
-		diffcore_rename(detect_rename, rename_score);
-	if (break_opt != -1)
+	if (options->paths && options->paths[0])
+		diffcore_pathspec(options->paths);
+	if (options->break_opt != -1)
+		diffcore_break(options->break_opt);
+	if (options->detect_rename)
+		diffcore_rename(options);
+	if (options->break_opt != -1)
 		diffcore_merge_broken();
-	if (pickaxe)
-		diffcore_pickaxe(pickaxe, pickaxe_opts);
-	if (orderfile)
-		diffcore_order(orderfile);
+	if (options->pickaxe)
+		diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
+	if (options->orderfile)
+		diffcore_order(options->orderfile);
 	diff_resolve_rename_copy();
-	diffcore_apply_filter(filter);
+	diffcore_apply_filter(options->filter);
 }
 
 
-void diffcore_std_no_resolve(const char **paths,
-			     const char *pickaxe, int pickaxe_opts,
-			     const char *orderfile,
-			     const char *filter)
+void diffcore_std_no_resolve(struct diff_options *options)
 {
-	if (paths && paths[0])
-		diffcore_pathspec(paths);
-	if (pickaxe)
-		diffcore_pickaxe(pickaxe, pickaxe_opts);
-	if (orderfile)
-		diffcore_order(orderfile);
-	diffcore_apply_filter(filter);
+	if (options->pickaxe)
+		diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
+	if (options->orderfile)
+		diffcore_order(options->orderfile);
+	diffcore_apply_filter(options->filter);
 }
 
-void diff_addremove(int addremove, unsigned mode,
+void diff_addremove(struct diff_options *options,
+		    int addremove, unsigned mode,
 		    const unsigned char *sha1,
 		    const char *base, const char *path)
 {
@@ -1133,7 +1412,7 @@ void diff_addremove(int addremove, unsigned mode,
 	 * Before the final output happens, they are pruned after
 	 * merged into rename/copy pairs as appropriate.
 	 */
-	if (reverse_diff)
+	if (options->reverse_diff)
 		addremove = (addremove == '+' ? '-' :
 			     addremove == '-' ? '+' : addremove);
 
@@ -1150,30 +1429,8 @@ void diff_addremove(int addremove, unsigned mode,
 	diff_queue(&diff_queued_diff, one, two);
 }
 
-void diff_helper_input(unsigned old_mode,
-		       unsigned new_mode,
-		       const unsigned char *old_sha1,
-		       const unsigned char *new_sha1,
-		       const char *old_path,
-		       int status,
-		       int score,
-		       const char *new_path)
-{
-	struct diff_filespec *one, *two;
-	struct diff_filepair *dp;
-
-	one = alloc_filespec(old_path);
-	two = alloc_filespec(new_path);
-	if (old_mode)
-		fill_filespec(one, old_sha1, old_mode);
-	if (new_mode)
-		fill_filespec(two, new_sha1, new_mode);
-	dp = diff_queue(&diff_queued_diff, one, two);
-	dp->score = score * MAX_SCORE / 100;
-	dp->status = status;
-}
-
-void diff_change(unsigned old_mode, unsigned new_mode,
+void diff_change(struct diff_options *options,
+		 unsigned old_mode, unsigned new_mode,
 		 const unsigned char *old_sha1,
 		 const unsigned char *new_sha1,
 		 const char *base, const char *path) 
@@ -1181,7 +1438,7 @@ void diff_change(unsigned old_mode, unsigned new_mode,
 	char concatpath[PATH_MAX];
 	struct diff_filespec *one, *two;
 
-	if (reverse_diff) {
+	if (options->reverse_diff) {
 		unsigned tmp;
 		const unsigned char *tmp_c;
 		tmp = old_mode; old_mode = new_mode; new_mode = tmp;
@@ -1197,7 +1454,8 @@ void diff_change(unsigned old_mode, unsigned new_mode,
 	diff_queue(&diff_queued_diff, one, two);
 }
 
-void diff_unmerge(const char *path)
+void diff_unmerge(struct diff_options *options,
+		  const char *path)
 {
 	struct diff_filespec *one, *two;
 	one = alloc_filespec(path);