1 files changed, 271 insertions, 182 deletions

diff --git a/diff.c b/diff.c
index a178ed39bc..9c38258030 100644
--- a/diff.c
+++ b/diff.c
@@ -2,6 +2,7 @@
  * Copyright (C) 2005 Junio C Hamano
  */
 #include "cache.h"
+#include "config.h"
 #include "tempfile.h"
 #include "quote.h"
 #include "diff.h"
@@ -27,12 +28,12 @@
 #endif
 
 static int diff_detect_rename_default;
-static int diff_indent_heuristic; /* experimental */
-static int diff_compaction_heuristic; /* experimental */
+static int diff_indent_heuristic = 1;
 static int diff_rename_limit_default = 400;
 static int diff_suppress_blank_empty;
 static int diff_use_color_default = -1;
 static int diff_context_default = 3;
+static int diff_interhunk_context_default;
 static const char *diff_word_regex_cfg;
 static const char *external_diff_cmd_cfg;
 static const char *diff_order_file_cfg;
@@ -43,6 +44,7 @@ static int diff_stat_graph_width;
 static int diff_dirstat_permille_default = 30;
 static struct diff_options default_diff_options;
 static long diff_algorithm;
+static unsigned ws_error_highlight_default = WSEH_NEW;
 
 static char diff_colors[][COLOR_MAXLEN] = {
 	GIT_COLOR_RESET,
@@ -172,6 +174,43 @@ long parse_algorithm_value(const char *value)
 	return -1;
 }
 
+static int parse_one_token(const char **arg, const char *token)
+{
+	const char *rest;
+	if (skip_prefix(*arg, token, &rest) && (!*rest || *rest == ',')) {
+		*arg = rest;
+		return 1;
+	}
+	return 0;
+}
+
+static int parse_ws_error_highlight(const char *arg)
+{
+	const char *orig_arg = arg;
+	unsigned val = 0;
+
+	while (*arg) {
+		if (parse_one_token(&arg, "none"))
+			val = 0;
+		else if (parse_one_token(&arg, "default"))
+			val = WSEH_NEW;
+		else if (parse_one_token(&arg, "all"))
+			val = WSEH_NEW | WSEH_OLD | WSEH_CONTEXT;
+		else if (parse_one_token(&arg, "new"))
+			val |= WSEH_NEW;
+		else if (parse_one_token(&arg, "old"))
+			val |= WSEH_OLD;
+		else if (parse_one_token(&arg, "context"))
+			val |= WSEH_CONTEXT;
+		else {
+			return -1 - (int)(arg - orig_arg);
+		}
+		if (*arg)
+			arg++;
+	}
+	return val;
+}
+
 /*
  * These are to give UI layer defaults.
  * The core-level commands such as git-diff-files should
@@ -185,16 +224,8 @@ void init_diff_ui_defaults(void)
 
 int git_diff_heuristic_config(const char *var, const char *value, void *cb)
 {
-	if (!strcmp(var, "diff.indentheuristic")) {
+	if (!strcmp(var, "diff.indentheuristic"))
 		diff_indent_heuristic = git_config_bool(var, value);
-		if (diff_indent_heuristic)
-			diff_compaction_heuristic = 0;
-	}
-	if (!strcmp(var, "diff.compactionheuristic")) {
-		diff_compaction_heuristic = git_config_bool(var, value);
-		if (diff_compaction_heuristic)
-			diff_indent_heuristic = 0;
-	}
 	return 0;
 }
 
@@ -210,6 +241,12 @@ int git_diff_ui_config(const char *var, const char *value, void *cb)
 			return -1;
 		return 0;
 	}
+	if (!strcmp(var, "diff.interhunkcontext")) {
+		diff_interhunk_context_default = git_config_int(var, value);
+		if (diff_interhunk_context_default < 0)
+			return -1;
+		return 0;
+	}
 	if (!strcmp(var, "diff.renames")) {
 		diff_detect_rename_default = git_config_rename(var, value);
 		return 0;
@@ -254,10 +291,13 @@ int git_diff_ui_config(const char *var, const char *value, void *cb)
 		return 0;
 	}
 
-	if (git_diff_heuristic_config(var, value, cb) < 0)
-		return -1;
-	if (git_color_config(var, value, cb) < 0)
-		return -1;
+	if (!strcmp(var, "diff.wserrorhighlight")) {
+		int val = parse_ws_error_highlight(value);
+		if (val < 0)
+			return -1;
+		ws_error_highlight_default = val;
+		return 0;
+	}
 
 	return git_diff_basic_config(var, value, cb);
 }
@@ -306,6 +346,9 @@ int git_diff_basic_config(const char *var, const char *value, void *cb)
 	if (starts_with(var, "submodule."))
 		return parse_submodule_config_option(var, value);
 
+	if (git_diff_heuristic_config(var, value, cb) < 0)
+		return -1;
+
 	return git_default_config(var, value, cb);
 }
 
@@ -353,7 +396,7 @@ static struct diff_tempfile {
 	 */
 	const char *name;
 
-	char hex[GIT_SHA1_HEXSZ + 1];
+	char hex[GIT_MAX_HEXSZ + 1];
 	char mode[10];
 
 	/*
@@ -866,7 +909,7 @@ static int fn_out_diff_words_write_helper(FILE *fp,
 /*
  * '--color-words' algorithm can be described as:
  *
- *   1. collect a the minus/plus lines of a diff hunk, divided into
+ *   1. collect the minus/plus lines of a diff hunk, divided into
  *      minus-lines and plus-lines;
  *
  *   2. break both minus-lines and plus-lines into words and
@@ -1173,8 +1216,7 @@ static void free_diff_words_data(struct emit_callback *ecbdata)
 			regfree(ecbdata->diff_words->word_regex);
 			free(ecbdata->diff_words->word_regex);
 		}
-		free(ecbdata->diff_words);
-		ecbdata->diff_words = NULL;
+		FREE_AND_NULL(ecbdata->diff_words);
 	}
 }
 
@@ -1976,7 +2018,7 @@ static void show_dirstat(struct diff_options *options)
 		if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
 			diff_populate_filespec(p->one, 0);
 			diff_populate_filespec(p->two, 0);
-			diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
+			diffcore_count_changes(p->one, p->two, NULL, NULL,
 					       &copied, &added);
 			diff_free_filespec_data(p->one);
 			diff_free_filespec_data(p->two);
@@ -2019,7 +2061,7 @@ found_damage:
 		return;
 
 	/* Show all directories with more than x% of the changes */
-	qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
+	QSORT(dir.files, dir.nr, dirstat_compare);
 	gather_dirstat(options, &dir, changed, "", 0);
 }
 
@@ -2050,7 +2092,7 @@ static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *o
 			 * bytes per "line".
 			 * This is stupid and ugly, but very cheap...
 			 */
-			damage = (damage + 63) / 64;
+			damage = DIV_ROUND_UP(damage, 64);
 		ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
 		dir.files[dir.nr].name = file->name;
 		dir.files[dir.nr].changed = damage;
@@ -2063,7 +2105,7 @@ static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *o
 		return;
 
 	/* Show all directories with more than x% of the changes */
-	qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
+	QSORT(dir.files, dir.nr, dirstat_compare);
 	gather_dirstat(options, &dir, changed, "", 0);
 }
 
@@ -2657,13 +2699,13 @@ void free_filespec(struct diff_filespec *spec)
 	}
 }
 
-void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
-		   int sha1_valid, unsigned short mode)
+void fill_filespec(struct diff_filespec *spec, const struct object_id *oid,
+		   int oid_valid, unsigned short mode)
 {
 	if (mode) {
 		spec->mode = canon_mode(mode);
-		hashcpy(spec->oid.hash, sha1);
-		spec->oid_valid = sha1_valid;
+		oidcpy(&spec->oid, oid);
+		spec->oid_valid = oid_valid;
 	}
 }
 
@@ -2672,7 +2714,7 @@ void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
  * the work tree has that object contents, return true, so that
  * prepare_temp_file() does not have to inflate and extract.
  */
-static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
+static int reuse_worktree_file(const char *name, const struct object_id *oid, int want_file)
 {
 	const struct cache_entry *ce;
 	struct stat st;
@@ -2703,14 +2745,14 @@ static int reuse_worktree_file(const char *name, const unsigned char *sha1, int
 	 * objects however would tend to be slower as they need
 	 * to be individually opened and inflated.
 	 */
-	if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
+	if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(oid->hash))
 		return 0;
 
 	/*
 	 * Similarly, if we'd have to convert the file contents anyway, that
 	 * makes the optimization not worthwhile.
 	 */
-	if (!want_file && would_convert_to_git(name))
+	if (!want_file && would_convert_to_git(&the_index, name))
 		return 0;
 
 	len = strlen(name);
@@ -2723,7 +2765,7 @@ static int reuse_worktree_file(const char *name, const unsigned char *sha1, int
 	 * This is not the sha1 we are looking for, or
 	 * unreusable because it is not a regular file.
 	 */
-	if (hashcmp(sha1, ce->oid.hash) || !S_ISREG(ce->ce_mode))
+	if (oidcmp(oid, &ce->oid) || !S_ISREG(ce->ce_mode))
 		return 0;
 
 	/*
@@ -2797,7 +2839,7 @@ int diff_populate_filespec(struct diff_filespec *s, unsigned int flags)
 		return diff_populate_gitlink(s, size_only);
 
 	if (!s->oid_valid ||
-	    reuse_worktree_file(s->path, s->oid.hash, 0)) {
+	    reuse_worktree_file(s->path, &s->oid, 0)) {
 		struct strbuf buf = STRBUF_INIT;
 		struct stat st;
 		int fd;
@@ -2825,8 +2867,25 @@ int diff_populate_filespec(struct diff_filespec *s, unsigned int flags)
 			s->should_free = 1;
 			return 0;
 		}
-		if (size_only)
+
+		/*
+		 * Even if the caller would be happy with getting
+		 * only the size, we cannot return early at this
+		 * point if the path requires us to run the content
+		 * conversion.
+		 */
+		if (size_only && !would_convert_to_git(&the_index, s->path))
 			return 0;
+
+		/*
+		 * Note: this check uses xsize_t(st.st_size) that may
+		 * not be the true size of the blob after it goes
+		 * through convert_to_git().  This may not strictly be
+		 * correct, but the whole point of big_file_threshold
+		 * and is_binary check being that we want to avoid
+		 * opening the file and inspecting the contents, this
+		 * is probably fine.
+		 */
 		if ((flags & CHECK_BINARY) &&
 		    s->size > big_file_threshold && s->is_binary == -1) {
 			s->is_binary = 1;
@@ -2842,7 +2901,7 @@ int diff_populate_filespec(struct diff_filespec *s, unsigned int flags)
 		/*
 		 * Convert from working tree format to canonical git format
 		 */
-		if (convert_to_git(s->path, s->data, s->size, &buf, crlf_warn)) {
+		if (convert_to_git(&the_index, s->path, s->data, s->size, &buf, crlf_warn)) {
 			size_t size = 0;
 			munmap(s->data, s->size);
 			s->should_munmap = 0;
@@ -2889,8 +2948,7 @@ void diff_free_filespec_blob(struct diff_filespec *s)
 void diff_free_filespec_data(struct diff_filespec *s)
 {
 	diff_free_filespec_blob(s);
-	free(s->cnt_data);
-	s->cnt_data = NULL;
+	FREE_AND_NULL(s->cnt_data);
 }
 
 static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
@@ -2946,7 +3004,7 @@ static struct diff_tempfile *prepare_temp_file(const char *name,
 
 	if (!S_ISGITLINK(one->mode) &&
 	    (!one->oid_valid ||
-	     reuse_worktree_file(name, one->oid.hash, 1))) {
+	     reuse_worktree_file(name, &one->oid, 1))) {
 		struct stat st;
 		if (lstat(name, &st) < 0) {
 			if (errno == ENOENT)
@@ -2968,13 +3026,13 @@ static struct diff_tempfile *prepare_temp_file(const char *name,
 			/* we can borrow from the file in the work tree */
 			temp->name = name;
 			if (!one->oid_valid)
-				sha1_to_hex_r(temp->hex, null_sha1);
+				oid_to_hex_r(temp->hex, &null_oid);
 			else
-				sha1_to_hex_r(temp->hex, one->oid.hash);
+				oid_to_hex_r(temp->hex, &one->oid);
 			/* Even though we may sometimes borrow the
 			 * contents from the work tree, we always want
 			 * one->mode.  mode is trustworthy even when
-			 * !(one->sha1_valid), as long as
+			 * !(one->oid_valid), as long as
 			 * DIFF_FILE_VALID(one).
 			 */
 			xsnprintf(temp->mode, sizeof(temp->mode), "%06o", one->mode);
@@ -3049,6 +3107,22 @@ static int similarity_index(struct diff_filepair *p)
 	return p->score * 100 / MAX_SCORE;
 }
 
+static const char *diff_abbrev_oid(const struct object_id *oid, int abbrev)
+{
+	if (startup_info->have_repository)
+		return find_unique_abbrev(oid->hash, abbrev);
+	else {
+		char *hex = oid_to_hex(oid);
+		if (abbrev < 0)
+			abbrev = FALLBACK_DEFAULT_ABBREV;
+		if (abbrev > GIT_SHA1_HEXSZ)
+			die("BUG: oid abbreviation out of range: %d", abbrev);
+		if (abbrev)
+			hex[abbrev] = '\0';
+		return hex;
+	}
+}
+
 static void fill_metainfo(struct strbuf *msg,
 			  const char *name,
 			  const char *other,
@@ -3107,9 +3181,9 @@ static void fill_metainfo(struct strbuf *msg,
 			    (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
 				abbrev = 40;
 		}
-		strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,
-			    find_unique_abbrev(one->oid.hash, abbrev));
-		strbuf_addstr(msg, find_unique_abbrev(two->oid.hash, abbrev));
+		strbuf_addf(msg, "%s%sindex %s..%s", line_prefix, set,
+			    diff_abbrev_oid(&one->oid, abbrev),
+			    diff_abbrev_oid(&two->oid, abbrev));
 		if (one->mode == two->mode)
 			strbuf_addf(msg, " %06o", one->mode);
 		strbuf_addf(msg, "%s\n", reset);
@@ -3161,7 +3235,7 @@ static void run_diff_cmd(const char *pgm,
 		fprintf(o->file, "* Unmerged path %s\n", name);
 }
 
-static void diff_fill_sha1_info(struct diff_filespec *one)
+static void diff_fill_oid_info(struct diff_filespec *one)
 {
 	if (DIFF_FILE_VALID(one)) {
 		if (!one->oid_valid) {
@@ -3220,8 +3294,8 @@ static void run_diff(struct diff_filepair *p, struct diff_options *o)
 		return;
 	}
 
-	diff_fill_sha1_info(one);
-	diff_fill_sha1_info(two);
+	diff_fill_oid_info(one);
+	diff_fill_oid_info(two);
 
 	if (!pgm &&
 	    DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
@@ -3266,8 +3340,8 @@ static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
 	if (o->prefix_length)
 		strip_prefix(o->prefix_length, &name, &other);
 
-	diff_fill_sha1_info(p->one);
-	diff_fill_sha1_info(p->two);
+	diff_fill_oid_info(p->one);
+	diff_fill_oid_info(p->two);
 
 	builtin_diffstat(name, other, p->one, p->two, diffstat, o, p);
 }
@@ -3290,8 +3364,8 @@ static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
 	if (o->prefix_length)
 		strip_prefix(o->prefix_length, &name, &other);
 
-	diff_fill_sha1_info(p->one);
-	diff_fill_sha1_info(p->two);
+	diff_fill_oid_info(p->one);
+	diff_fill_oid_info(p->two);
 
 	builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
 }
@@ -3302,12 +3376,14 @@ void diff_setup(struct diff_options *options)
 
 	options->file = stdout;
 
+	options->abbrev = DEFAULT_ABBREV;
 	options->line_termination = '\n';
 	options->break_opt = -1;
 	options->rename_limit = -1;
 	options->dirstat_permille = diff_dirstat_permille_default;
 	options->context = diff_context_default;
-	options->ws_error_highlight = WSEH_NEW;
+	options->interhunkcontext = diff_interhunk_context_default;
+	options->ws_error_highlight = ws_error_highlight_default;
 	DIFF_OPT_SET(options, RENAME_EMPTY);
 
 	/* pathchange left =NULL by default */
@@ -3318,8 +3394,6 @@ void diff_setup(struct diff_options *options)
 	options->xdl_opts |= diff_algorithm;
 	if (diff_indent_heuristic)
 		DIFF_XDL_SET(options, INDENT_HEURISTIC);
-	else if (diff_compaction_heuristic)
-		DIFF_XDL_SET(options, COMPACTION_HEURISTIC);
 
 	options->orderfile = diff_order_file_cfg;
 
@@ -3421,7 +3495,7 @@ void diff_setup_done(struct diff_options *options)
 			 */
 			read_cache();
 	}
-	if (options->abbrev <= 0 || 40 < options->abbrev)
+	if (40 < options->abbrev)
 		options->abbrev = 40; /* full */
 
 	/*
@@ -3698,40 +3772,14 @@ static void enable_patch_output(int *fmt) {
 	*fmt |= DIFF_FORMAT_PATCH;
 }
 
-static int parse_one_token(const char **arg, const char *token)
+static int parse_ws_error_highlight_opt(struct diff_options *opt, const char *arg)
 {
-	const char *rest;
-	if (skip_prefix(*arg, token, &rest) && (!*rest || *rest == ',')) {
-		*arg = rest;
-		return 1;
-	}
-	return 0;
-}
+	int val = parse_ws_error_highlight(arg);
 
-static int parse_ws_error_highlight(struct diff_options *opt, const char *arg)
-{
-	const char *orig_arg = arg;
-	unsigned val = 0;
-	while (*arg) {
-		if (parse_one_token(&arg, "none"))
-			val = 0;
-		else if (parse_one_token(&arg, "default"))
-			val = WSEH_NEW;
-		else if (parse_one_token(&arg, "all"))
-			val = WSEH_NEW | WSEH_OLD | WSEH_CONTEXT;
-		else if (parse_one_token(&arg, "new"))
-			val |= WSEH_NEW;
-		else if (parse_one_token(&arg, "old"))
-			val |= WSEH_OLD;
-		else if (parse_one_token(&arg, "context"))
-			val |= WSEH_CONTEXT;
-		else {
-			error("unknown value after ws-error-highlight=%.*s",
-			      (int)(arg - orig_arg), orig_arg);
-			return 0;
-		}
-		if (*arg)
-			arg++;
+	if (val < 0) {
+		error("unknown value after ws-error-highlight=%.*s",
+		      -1 - val, arg);
+		return 0;
 	}
 	opt->ws_error_highlight = val;
 	return 1;
@@ -3840,16 +3888,10 @@ int diff_opt_parse(struct diff_options *options,
 		DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
 	else if (!strcmp(arg, "--ignore-blank-lines"))
 		DIFF_XDL_SET(options, IGNORE_BLANK_LINES);
-	else if (!strcmp(arg, "--indent-heuristic")) {
+	else if (!strcmp(arg, "--indent-heuristic"))
 		DIFF_XDL_SET(options, INDENT_HEURISTIC);
-		DIFF_XDL_CLR(options, COMPACTION_HEURISTIC);
-	} else if (!strcmp(arg, "--no-indent-heuristic"))
+	else if (!strcmp(arg, "--no-indent-heuristic"))
 		DIFF_XDL_CLR(options, INDENT_HEURISTIC);
-	else if (!strcmp(arg, "--compaction-heuristic")) {
-		DIFF_XDL_SET(options, COMPACTION_HEURISTIC);
-		DIFF_XDL_CLR(options, INDENT_HEURISTIC);
-	} else if (!strcmp(arg, "--no-compaction-heuristic"))
-		DIFF_XDL_CLR(options, COMPACTION_HEURISTIC);
 	else if (!strcmp(arg, "--patience"))
 		options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
 	else if (!strcmp(arg, "--histogram"))
@@ -3950,7 +3992,11 @@ int diff_opt_parse(struct diff_options *options,
 	else if (skip_prefix(arg, "--submodule=", &arg))
 		return parse_submodule_opt(options, arg);
 	else if (skip_prefix(arg, "--ws-error-highlight=", &arg))
-		return parse_ws_error_highlight(options, arg);
+		return parse_ws_error_highlight_opt(options, arg);
+	else if (!strcmp(arg, "--ita-invisible-in-index"))
+		options->ita_invisible_in_index = 1;
+	else if (!strcmp(arg, "--ita-visible-in-index"))
+		options->ita_invisible_in_index = 0;
 
 	/* misc options */
 	else if (!strcmp(arg, "-z"))
@@ -3973,8 +4019,7 @@ int diff_opt_parse(struct diff_options *options,
 	else if (!strcmp(arg, "--pickaxe-regex"))
 		options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
 	else if ((argcount = short_opt('O', av, &optarg))) {
-		const char *path = prefix_filename(prefix, strlen(prefix), optarg);
-		options->orderfile = xstrdup(path);
+		options->orderfile = prefix_filename(prefix, optarg);
 		return argcount;
 	}
 	else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
@@ -3984,6 +4029,8 @@ int diff_opt_parse(struct diff_options *options,
 			    offending, optarg);
 		return argcount;
 	}
+	else if (!strcmp(arg, "--no-abbrev"))
+		options->abbrev = 0;
 	else if (!strcmp(arg, "--abbrev"))
 		options->abbrev = DEFAULT_ABBREV;
 	else if (skip_prefix(arg, "--abbrev=", &arg)) {
@@ -4019,13 +4066,12 @@ int diff_opt_parse(struct diff_options *options,
 	else if (!strcmp(arg, "--no-function-context"))
 		DIFF_OPT_CLR(options, FUNCCONTEXT);
 	else if ((argcount = parse_long_opt("output", av, &optarg))) {
-		const char *path = prefix_filename(prefix, strlen(prefix), optarg);
-		options->file = fopen(path, "w");
-		if (!options->file)
-			die_errno("Could not open '%s'", path);
+		char *path = prefix_filename(prefix, optarg);
+		options->file = xfopen(path, "w");
 		options->close_file = 1;
 		if (options->use_color != GIT_COLOR_ALWAYS)
 			options->use_color = GIT_COLOR_NEVER;
+		free(path);
 		return argcount;
 	} else
 		return 0;
@@ -4136,27 +4182,46 @@ void diff_free_filepair(struct diff_filepair *p)
 	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)
+const char *diff_aligned_abbrev(const struct object_id *oid, int len)
 {
 	int abblen;
 	const char *abbrev;
-	if (len == 40)
-		return sha1_to_hex(sha1);
 
-	abbrev = find_unique_abbrev(sha1, len);
+	if (len == GIT_SHA1_HEXSZ)
+		return oid_to_hex(oid);
+
+	abbrev = diff_abbrev_oid(oid, len);
 	abblen = strlen(abbrev);
-	if (abblen < 37) {
-		static char hex[41];
+
+	/*
+	 * In well-behaved cases, where the abbbreviated result is the
+	 * same as the requested length, append three dots after the
+	 * abbreviation (hence the whole logic is limited to the case
+	 * where abblen < 37); when the actual abbreviated result is a
+	 * bit longer than the requested length, we reduce the number
+	 * of dots so that they match the well-behaved ones.  However,
+	 * if the actual abbreviation is longer than the requested
+	 * length by more than three, we give up on aligning, and add
+	 * three dots anyway, to indicate that the output is not the
+	 * full object name.  Yes, this may be suboptimal, but this
+	 * appears only in "diff --raw --abbrev" output and it is not
+	 * worth the effort to change it now.  Note that this would
+	 * likely to work fine when the automatic sizing of default
+	 * abbreviation length is used--we would be fed -1 in "len" in
+	 * that case, and will end up always appending three-dots, but
+	 * the automatic sizing is supposed to give abblen that ensures
+	 * uniqueness across all objects (statistically speaking).
+	 */
+	if (abblen < GIT_SHA1_HEXSZ - 3) {
+		static char hex[GIT_MAX_HEXSZ + 1];
 		if (len < abblen && abblen <= len + 2)
 			xsnprintf(hex, sizeof(hex), "%s%.*s", abbrev, len+3-abblen, "..");
 		else
 			xsnprintf(hex, sizeof(hex), "%s...", abbrev);
 		return hex;
 	}
-	return sha1_to_hex(sha1);
+
+	return oid_to_hex(oid);
 }
 
 static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
@@ -4167,9 +4232,9 @@ static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
 	fprintf(opt->file, "%s", diff_line_prefix(opt));
 	if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
 		fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
-			diff_unique_abbrev(p->one->oid.hash, opt->abbrev));
+			diff_aligned_abbrev(&p->one->oid, opt->abbrev));
 		fprintf(opt->file, "%s ",
-			diff_unique_abbrev(p->two->oid.hash, opt->abbrev));
+			diff_aligned_abbrev(&p->two->oid, opt->abbrev));
 	}
 	if (p->score) {
 		fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
@@ -4396,6 +4461,7 @@ static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
 		name_a = p->two->path;
 		name_b = NULL;
 		strip_prefix(opt->prefix_length, &name_a, &name_b);
+		fprintf(opt->file, "%s", diff_line_prefix(opt));
 		write_name_quoted(name_a, opt->file, opt->line_termination);
 	}
 }
@@ -4498,14 +4564,26 @@ static void patch_id_consume(void *priv, char *line, unsigned long len)
 	data->patchlen += new_len;
 }
 
+static void patch_id_add_string(git_SHA_CTX *ctx, const char *str)
+{
+	git_SHA1_Update(ctx, str, strlen(str));
+}
+
+static void patch_id_add_mode(git_SHA_CTX *ctx, unsigned mode)
+{
+	/* large enough for 2^32 in octal */
+	char buf[12];
+	int len = xsnprintf(buf, sizeof(buf), "%06o", mode);
+	git_SHA1_Update(ctx, buf, len);
+}
+
 /* returns 0 upon success, and writes result into sha1 */
-static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1, int diff_header_only)
+static int diff_get_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
 {
 	struct diff_queue_struct *q = &diff_queued_diff;
 	int i;
 	git_SHA_CTX ctx;
 	struct patch_id_t data;
-	char buffer[PATH_MAX * 4 + 20];
 
 	git_SHA1_Init(&ctx);
 	memset(&data, 0, sizeof(struct patch_id_t));
@@ -4532,41 +4610,35 @@ static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1,
 		if (DIFF_PAIR_UNMERGED(p))
 			continue;
 
-		diff_fill_sha1_info(p->one);
-		diff_fill_sha1_info(p->two);
+		diff_fill_oid_info(p->one);
+		diff_fill_oid_info(p->two);
 
 		len1 = remove_space(p->one->path, strlen(p->one->path));
 		len2 = remove_space(p->two->path, strlen(p->two->path));
-		if (p->one->mode == 0)
-			len1 = snprintf(buffer, sizeof(buffer),
-					"diff--gita/%.*sb/%.*s"
-					"newfilemode%06o"
-					"---/dev/null"
-					"+++b/%.*s",
-					len1, p->one->path,
-					len2, p->two->path,
-					p->two->mode,
-					len2, p->two->path);
-		else if (p->two->mode == 0)
-			len1 = snprintf(buffer, sizeof(buffer),
-					"diff--gita/%.*sb/%.*s"
-					"deletedfilemode%06o"
-					"---a/%.*s"
-					"+++/dev/null",
-					len1, p->one->path,
-					len2, p->two->path,
-					p->one->mode,
-					len1, p->one->path);
-		else
-			len1 = snprintf(buffer, sizeof(buffer),
-					"diff--gita/%.*sb/%.*s"
-					"---a/%.*s"
-					"+++b/%.*s",
-					len1, p->one->path,
-					len2, p->two->path,
-					len1, p->one->path,
-					len2, p->two->path);
-		git_SHA1_Update(&ctx, buffer, len1);
+		patch_id_add_string(&ctx, "diff--git");
+		patch_id_add_string(&ctx, "a/");
+		git_SHA1_Update(&ctx, p->one->path, len1);
+		patch_id_add_string(&ctx, "b/");
+		git_SHA1_Update(&ctx, p->two->path, len2);
+
+		if (p->one->mode == 0) {
+			patch_id_add_string(&ctx, "newfilemode");
+			patch_id_add_mode(&ctx, p->two->mode);
+			patch_id_add_string(&ctx, "---/dev/null");
+			patch_id_add_string(&ctx, "+++b/");
+			git_SHA1_Update(&ctx, p->two->path, len2);
+		} else if (p->two->mode == 0) {
+			patch_id_add_string(&ctx, "deletedfilemode");
+			patch_id_add_mode(&ctx, p->one->mode);
+			patch_id_add_string(&ctx, "---a/");
+			git_SHA1_Update(&ctx, p->one->path, len1);
+			patch_id_add_string(&ctx, "+++/dev/null");
+		} else {
+			patch_id_add_string(&ctx, "---a/");
+			git_SHA1_Update(&ctx, p->one->path, len1);
+			patch_id_add_string(&ctx, "+++b/");
+			git_SHA1_Update(&ctx, p->two->path, len2);
+		}
 
 		if (diff_header_only)
 			continue;
@@ -4578,9 +4650,9 @@ static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1,
 		if (diff_filespec_is_binary(p->one) ||
 		    diff_filespec_is_binary(p->two)) {
 			git_SHA1_Update(&ctx, oid_to_hex(&p->one->oid),
-					40);
+					GIT_SHA1_HEXSZ);
 			git_SHA1_Update(&ctx, oid_to_hex(&p->two->oid),
-					40);
+					GIT_SHA1_HEXSZ);
 			continue;
 		}
 
@@ -4593,15 +4665,15 @@ static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1,
 				     p->one->path);
 	}
 
-	git_SHA1_Final(sha1, &ctx);
+	git_SHA1_Final(oid->hash, &ctx);
 	return 0;
 }
 
-int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1, int diff_header_only)
+int diff_flush_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
 {
 	struct diff_queue_struct *q = &diff_queued_diff;
 	int i;
-	int result = diff_get_patch_id(options, sha1, diff_header_only);
+	int result = diff_get_patch_id(options, oid, diff_header_only);
 
 	for (i = 0; i < q->nr; i++)
 		diff_free_filepair(q->queue[i]);
@@ -4638,25 +4710,25 @@ static int is_summary_empty(const struct diff_queue_struct *q)
 }
 
 static const char rename_limit_warning[] =
-"inexact rename detection was skipped due to too many files.";
+N_("inexact rename detection was skipped due to too many files.");
 
 static const char degrade_cc_to_c_warning[] =
-"only found copies from modified paths due to too many files.";
+N_("only found copies from modified paths due to too many files.");
 
 static const char rename_limit_advice[] =
-"you may want to set your %s variable to at least "
-"%d and retry the command.";
+N_("you may want to set your %s variable to at least "
+   "%d and retry the command.");
 
 void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
 {
 	if (degraded_cc)
-		warning(degrade_cc_to_c_warning);
+		warning(_(degrade_cc_to_c_warning));
 	else if (needed)
-		warning(rename_limit_warning);
+		warning(_(rename_limit_warning));
 	else
 		return;
 	if (0 < needed && needed < 32767)
-		warning(rename_limit_advice, varname, needed);
+		warning(_(rename_limit_advice), varname, needed);
 }
 
 void diff_flush(struct diff_options *options)
@@ -4729,9 +4801,7 @@ void diff_flush(struct diff_options *options)
 		 */
 		if (options->close_file)
 			fclose(options->file);
-		options->file = fopen("/dev/null", "w");
-		if (!options->file)
-			die_errno("Could not open /dev/null");
+		options->file = xfopen("/dev/null", "w");
 		options->close_file = 1;
 		for (i = 0; i < q->nr; i++) {
 			struct diff_filepair *p = q->queue[i];
@@ -4923,7 +4993,7 @@ static int diffnamecmp(const void *a_, const void *b_)
 void diffcore_fix_diff_index(struct diff_options *options)
 {
 	struct diff_queue_struct *q = &diff_queued_diff;
-	qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
+	QSORT(q->queue, q->nr, diffnamecmp);
 }
 
 void diffcore_std(struct diff_options *options)
@@ -5003,8 +5073,8 @@ static int is_submodule_ignored(const char *path, struct diff_options *options)
 
 void diff_addremove(struct diff_options *options,
 		    int addremove, unsigned mode,
-		    const unsigned char *sha1,
-		    int sha1_valid,
+		    const struct object_id *oid,
+		    int oid_valid,
 		    const char *concatpath, unsigned dirty_submodule)
 {
 	struct diff_filespec *one, *two;
@@ -5036,9 +5106,9 @@ void diff_addremove(struct diff_options *options,
 	two = alloc_filespec(concatpath);
 
 	if (addremove != '+')
-		fill_filespec(one, sha1, sha1_valid, mode);
+		fill_filespec(one, oid, oid_valid, mode);
 	if (addremove != '-') {
-		fill_filespec(two, sha1, sha1_valid, mode);
+		fill_filespec(two, oid, oid_valid, mode);
 		two->dirty_submodule = dirty_submodule;
 	}
 
@@ -5049,9 +5119,9 @@ void diff_addremove(struct diff_options *options,
 
 void diff_change(struct diff_options *options,
 		 unsigned old_mode, unsigned new_mode,
-		 const unsigned char *old_sha1,
-		 const unsigned char *new_sha1,
-		 int old_sha1_valid, int new_sha1_valid,
+		 const struct object_id *old_oid,
+		 const struct object_id *new_oid,
+		 int old_oid_valid, int new_oid_valid,
 		 const char *concatpath,
 		 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
 {
@@ -5063,14 +5133,10 @@ void diff_change(struct diff_options *options,
 		return;
 
 	if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
-		unsigned tmp;
-		const unsigned char *tmp_c;
-		tmp = old_mode; old_mode = new_mode; new_mode = tmp;
-		tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
-		tmp = old_sha1_valid; old_sha1_valid = new_sha1_valid;
-			new_sha1_valid = tmp;
-		tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
-			new_dirty_submodule = tmp;
+		SWAP(old_mode, new_mode);
+		SWAP(old_oid, new_oid);
+		SWAP(old_oid_valid, new_oid_valid);
+		SWAP(old_dirty_submodule, new_dirty_submodule);
 	}
 
 	if (options->prefix &&
@@ -5079,8 +5145,8 @@ void diff_change(struct diff_options *options,
 
 	one = alloc_filespec(concatpath);
 	two = alloc_filespec(concatpath);
-	fill_filespec(one, old_sha1, old_sha1_valid, old_mode);
-	fill_filespec(two, new_sha1, new_sha1_valid, new_mode);
+	fill_filespec(one, old_oid, old_oid_valid, old_mode);
+	fill_filespec(two, new_oid, new_oid_valid, new_mode);
 	one->dirty_submodule = old_dirty_submodule;
 	two->dirty_submodule = new_dirty_submodule;
 	p = diff_queue(&diff_queued_diff, one, two);
@@ -5170,7 +5236,7 @@ size_t fill_textconv(struct userdiff_driver *driver,
 
 	if (driver->textconv_cache && df->oid_valid) {
 		*outbuf = notes_cache_get(driver->textconv_cache,
-					  df->oid.hash,
+					  &df->oid,
 					  &size);
 		if (*outbuf)
 			return size;
@@ -5182,7 +5248,7 @@ size_t fill_textconv(struct userdiff_driver *driver,
 
 	if (driver->textconv_cache && df->oid_valid) {
 		/* ignore errors, as we might be in a readonly repository */
-		notes_cache_put(driver->textconv_cache, df->oid.hash, *outbuf,
+		notes_cache_put(driver->textconv_cache, &df->oid, *outbuf,
 				size);
 		/*
 		 * we could save up changes and flush them all at the end,
@@ -5196,6 +5262,29 @@ size_t fill_textconv(struct userdiff_driver *driver,
 	return size;
 }
 
+int textconv_object(const char *path,
+		    unsigned mode,
+		    const struct object_id *oid,
+		    int oid_valid,
+		    char **buf,
+		    unsigned long *buf_size)
+{
+	struct diff_filespec *df;
+	struct userdiff_driver *textconv;
+
+	df = alloc_filespec(path);
+	fill_filespec(df, oid, oid_valid, mode);
+	textconv = get_textconv(df);
+	if (!textconv) {
+		free_filespec(df);
+		return 0;
+	}
+
+	*buf_size = fill_textconv(textconv, df, buf);
+	free_filespec(df);
+	return 1;
+}
+
 void setup_diff_pager(struct diff_options *opt)
 {
 	/*