1 files changed, 211 insertions, 100 deletions

diff --git a/diff.c b/diff.c
index 7500c55095..d3734d3181 100644
--- a/diff.c
+++ b/diff.c
@@ -2,6 +2,7 @@
  * Copyright (C) 2005 Junio C Hamano
  */
 #include "cache.h"
+#include "tempfile.h"
 #include "quote.h"
 #include "diff.h"
 #include "diffcore.h"
@@ -12,7 +13,7 @@
 #include "run-command.h"
 #include "utf8.h"
 #include "userdiff.h"
-#include "sigchain.h"
+#include "submodule-config.h"
 #include "submodule.h"
 #include "ll-merge.h"
 #include "string-list.h"
@@ -25,6 +26,7 @@
 #endif
 
 static int diff_detect_rename_default;
+static int diff_compaction_heuristic = 1;
 static int diff_rename_limit_default = 400;
 static int diff_suppress_blank_empty;
 static int diff_use_color_default = -1;
@@ -42,7 +44,7 @@ static long diff_algorithm;
 
 static char diff_colors[][COLOR_MAXLEN] = {
 	GIT_COLOR_RESET,
-	GIT_COLOR_NORMAL,	/* PLAIN */
+	GIT_COLOR_NORMAL,	/* CONTEXT */
 	GIT_COLOR_BOLD,		/* METAINFO */
 	GIT_COLOR_CYAN,		/* FRAGINFO */
 	GIT_COLOR_RED,		/* OLD */
@@ -54,8 +56,8 @@ static char diff_colors[][COLOR_MAXLEN] = {
 
 static int parse_diff_color_slot(const char *var)
 {
-	if (!strcasecmp(var, "plain"))
-		return DIFF_PLAIN;
+	if (!strcasecmp(var, "context") || !strcasecmp(var, "plain"))
+		return DIFF_CONTEXT;
 	if (!strcasecmp(var, "meta"))
 		return DIFF_METAINFO;
 	if (!strcasecmp(var, "frag"))
@@ -167,6 +169,11 @@ long parse_algorithm_value(const char *value)
  * never be affected by the setting of diff.renames
  * the user happens to have in the configuration file.
  */
+void init_diff_ui_defaults(void)
+{
+	diff_detect_rename_default = 1;
+}
+
 int git_diff_ui_config(const char *var, const char *value, void *cb)
 {
 	if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
@@ -183,6 +190,10 @@ int git_diff_ui_config(const char *var, const char *value, void *cb)
 		diff_detect_rename_default = git_config_rename(var, value);
 		return 0;
 	}
+	if (!strcmp(var, "diff.compactionheuristic")) {
+		diff_compaction_heuristic = git_config_bool(var, value);
+		return 0;
+	}
 	if (!strcmp(var, "diff.autorefreshindex")) {
 		diff_auto_refresh_index = git_config_bool(var, value);
 		return 0;
@@ -308,11 +319,26 @@ static const char *external_diff(void)
 	return external_diff_cmd;
 }
 
+/*
+ * Keep track of files used for diffing. Sometimes such an entry
+ * refers to a temporary file, sometimes to an existing file, and
+ * sometimes to "/dev/null".
+ */
 static struct diff_tempfile {
-	const char *name; /* filename external diff should read from */
-	char hex[41];
+	/*
+	 * filename external diff should read from, or NULL if this
+	 * entry is currently not in use:
+	 */
+	const char *name;
+
+	char hex[GIT_SHA1_HEXSZ + 1];
 	char mode[10];
-	char tmp_path[PATH_MAX];
+
+	/*
+	 * If this diff_tempfile instance refers to a temporary file,
+	 * this tempfile object is used to manage its lifetime.
+	 */
+	struct tempfile tempfile;
 } diff_temp[2];
 
 typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
@@ -478,30 +504,63 @@ static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line
 	return ws_blank_line(line, len, ecbdata->ws_rule);
 }
 
-static void emit_add_line(const char *reset,
-			  struct emit_callback *ecbdata,
-			  const char *line, int len)
+static void emit_line_checked(const char *reset,
+			      struct emit_callback *ecbdata,
+			      const char *line, int len,
+			      enum color_diff color,
+			      unsigned ws_error_highlight,
+			      char sign)
 {
-	const char *ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
-	const char *set = diff_get_color(ecbdata->color_diff, DIFF_FILE_NEW);
+	const char *set = diff_get_color(ecbdata->color_diff, color);
+	const char *ws = NULL;
+
+	if (ecbdata->opt->ws_error_highlight & ws_error_highlight) {
+		ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
+		if (!*ws)
+			ws = NULL;
+	}
 
-	if (!*ws)
-		emit_line_0(ecbdata->opt, set, reset, '+', line, len);
-	else if (new_blank_line_at_eof(ecbdata, line, len))
+	if (!ws)
+		emit_line_0(ecbdata->opt, set, reset, sign, line, len);
+	else if (sign == '+' && new_blank_line_at_eof(ecbdata, line, len))
 		/* Blank line at EOF - paint '+' as well */
-		emit_line_0(ecbdata->opt, ws, reset, '+', line, len);
+		emit_line_0(ecbdata->opt, ws, reset, sign, line, len);
 	else {
 		/* Emit just the prefix, then the rest. */
-		emit_line_0(ecbdata->opt, set, reset, '+', "", 0);
+		emit_line_0(ecbdata->opt, set, reset, sign, "", 0);
 		ws_check_emit(line, len, ecbdata->ws_rule,
 			      ecbdata->opt->file, set, reset, ws);
 	}
 }
 
+static void emit_add_line(const char *reset,
+			  struct emit_callback *ecbdata,
+			  const char *line, int len)
+{
+	emit_line_checked(reset, ecbdata, line, len,
+			  DIFF_FILE_NEW, WSEH_NEW, '+');
+}
+
+static void emit_del_line(const char *reset,
+			  struct emit_callback *ecbdata,
+			  const char *line, int len)
+{
+	emit_line_checked(reset, ecbdata, line, len,
+			  DIFF_FILE_OLD, WSEH_OLD, '-');
+}
+
+static void emit_context_line(const char *reset,
+			      struct emit_callback *ecbdata,
+			      const char *line, int len)
+{
+	emit_line_checked(reset, ecbdata, line, len,
+			  DIFF_CONTEXT, WSEH_CONTEXT, ' ');
+}
+
 static void emit_hunk_header(struct emit_callback *ecbdata,
 			     const char *line, int len)
 {
-	const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
+	const char *context = diff_get_color(ecbdata->color_diff, DIFF_CONTEXT);
 	const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
 	const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
 	const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
@@ -518,7 +577,7 @@ static void emit_hunk_header(struct emit_callback *ecbdata,
 	if (len < 10 ||
 	    memcmp(line, atat, 2) ||
 	    !(ep = memmem(line + 2, len - 2, atat, 2))) {
-		emit_line(ecbdata->opt, plain, reset, line, len);
+		emit_line(ecbdata->opt, context, reset, line, len);
 		return;
 	}
 	ep += 2; /* skip over @@ */
@@ -540,7 +599,7 @@ static void emit_hunk_header(struct emit_callback *ecbdata,
 		if (*ep != ' ' && *ep != '\t')
 			break;
 	if (ep != cp) {
-		strbuf_addstr(&msgbuf, plain);
+		strbuf_addstr(&msgbuf, context);
 		strbuf_add(&msgbuf, cp, ep - cp);
 		strbuf_addstr(&msgbuf, reset);
 	}
@@ -564,25 +623,16 @@ static struct diff_tempfile *claim_diff_tempfile(void) {
 	die("BUG: diff is failing to clean up its tempfiles");
 }
 
-static int remove_tempfile_installed;
-
 static void remove_tempfile(void)
 {
 	int i;
 	for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
-		if (diff_temp[i].name == diff_temp[i].tmp_path)
-			unlink_or_warn(diff_temp[i].name);
+		if (is_tempfile_active(&diff_temp[i].tempfile))
+			delete_tempfile(&diff_temp[i].tempfile);
 		diff_temp[i].name = NULL;
 	}
 }
 
-static void remove_tempfile_on_signal(int signo)
-{
-	remove_tempfile();
-	sigchain_pop(signo);
-	raise(signo);
-}
-
 static void print_line_count(FILE *file, int count)
 {
 	switch (count) {
@@ -603,7 +653,6 @@ static void emit_rewrite_lines(struct emit_callback *ecb,
 {
 	const char *endp = NULL;
 	static const char *nneof = " No newline at end of file\n";
-	const char *old = diff_get_color(ecb->color_diff, DIFF_FILE_OLD);
 	const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
 
 	while (0 < size) {
@@ -613,8 +662,7 @@ static void emit_rewrite_lines(struct emit_callback *ecb,
 		len = endp ? (endp - data + 1) : size;
 		if (prefix != '+') {
 			ecb->lno_in_preimage++;
-			emit_line_0(ecb->opt, old, reset, '-',
-				    data, len);
+			emit_del_line(reset, ecb, data, len);
 		} else {
 			ecb->lno_in_postimage++;
 			emit_add_line(reset, ecb, data, len);
@@ -623,10 +671,10 @@ static void emit_rewrite_lines(struct emit_callback *ecb,
 		data += len;
 	}
 	if (!endp) {
-		const char *plain = diff_get_color(ecb->color_diff,
-						   DIFF_PLAIN);
+		const char *context = diff_get_color(ecb->color_diff,
+						     DIFF_CONTEXT);
 		putc('\n', ecb->opt->file);
-		emit_line_0(ecb->opt, plain, reset, '\\',
+		emit_line_0(ecb->opt, context, reset, '\\',
 			    nneof, strlen(nneof));
 	}
 }
@@ -1002,8 +1050,9 @@ static void diff_words_show(struct diff_words_data *diff_words)
 	xpp.flags = 0;
 	/* as only the hunk header will be parsed, we need a 0-context */
 	xecfg.ctxlen = 0;
-	xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
-		      &xpp, &xecfg);
+	if (xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
+			  &xpp, &xecfg))
+		die("unable to generate word diff");
 	free(minus.ptr);
 	free(plus.ptr);
 	if (diff_words->current_plus != diff_words->plus.text.ptr +
@@ -1086,7 +1135,7 @@ static void init_diff_words_data(struct emit_callback *ecbdata,
 		struct diff_words_style *st = ecbdata->diff_words->style;
 		st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
 		st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
-		st->ctx.color = diff_get_color_opt(o, DIFF_PLAIN);
+		st->ctx.color = diff_get_color_opt(o, DIFF_CONTEXT);
 	}
 }
 
@@ -1162,7 +1211,7 @@ static void fn_out_consume(void *priv, char *line, unsigned long len)
 {
 	struct emit_callback *ecbdata = priv;
 	const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
-	const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
+	const char *context = diff_get_color(ecbdata->color_diff, DIFF_CONTEXT);
 	const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 	struct diff_options *o = ecbdata->opt;
 	const char *line_prefix = diff_line_prefix(o);
@@ -1233,7 +1282,7 @@ static void fn_out_consume(void *priv, char *line, unsigned long len)
 		}
 		diff_words_flush(ecbdata);
 		if (ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN) {
-			emit_line(ecbdata->opt, plain, reset, line, len);
+			emit_line(ecbdata->opt, context, reset, line, len);
 			fputs("~\n", ecbdata->opt->file);
 		} else {
 			/*
@@ -1245,22 +1294,32 @@ static void fn_out_consume(void *priv, char *line, unsigned long len)
 			      line++;
 			      len--;
 			}
-			emit_line(ecbdata->opt, plain, reset, line, len);
+			emit_line(ecbdata->opt, context, reset, line, len);
 		}
 		return;
 	}
 
-	if (line[0] != '+') {
-		const char *color =
-			diff_get_color(ecbdata->color_diff,
-				       line[0] == '-' ? DIFF_FILE_OLD : DIFF_PLAIN);
-		ecbdata->lno_in_preimage++;
-		if (line[0] == ' ')
-			ecbdata->lno_in_postimage++;
-		emit_line(ecbdata->opt, color, reset, line, len);
-	} else {
+	switch (line[0]) {
+	case '+':
 		ecbdata->lno_in_postimage++;
 		emit_add_line(reset, ecbdata, line + 1, len - 1);
+		break;
+	case '-':
+		ecbdata->lno_in_preimage++;
+		emit_del_line(reset, ecbdata, line + 1, len - 1);
+		break;
+	case ' ':
+		ecbdata->lno_in_postimage++;
+		ecbdata->lno_in_preimage++;
+		emit_context_line(reset, ecbdata, line + 1, len - 1);
+		break;
+	default:
+		/* incomplete line at the end */
+		ecbdata->lno_in_preimage++;
+		emit_line(ecbdata->opt,
+			  diff_get_color(ecbdata->color_diff, DIFF_CONTEXT),
+			  reset, line, len);
+		break;
 	}
 }
 
@@ -2400,8 +2459,9 @@ static void builtin_diff(const char *name_a,
 			xecfg.ctxlen = strtoul(v, NULL, 10);
 		if (o->word_diff)
 			init_diff_words_data(&ecbdata, o, one, two);
-		xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
-			      &xpp, &xecfg);
+		if (xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
+				  &xpp, &xecfg))
+			die("unable to generate diff for %s", one->path);
 		if (o->word_diff)
 			free_diff_words_data(&ecbdata);
 		if (textconv_one)
@@ -2478,8 +2538,9 @@ static void builtin_diffstat(const char *name_a, const char *name_b,
 		xpp.flags = o->xdl_opts;
 		xecfg.ctxlen = o->context;
 		xecfg.interhunkctxlen = o->interhunkcontext;
-		xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
-			      &xpp, &xecfg);
+		if (xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
+				  &xpp, &xecfg))
+			die("unable to generate diffstat for %s", one->path);
 	}
 
 	diff_free_filespec_data(one);
@@ -2525,8 +2586,9 @@ static void builtin_checkdiff(const char *name_a, const char *name_b,
 		memset(&xecfg, 0, sizeof(xecfg));
 		xecfg.ctxlen = 1; /* at least one context line */
 		xpp.flags = 0;
-		xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
-			      &xpp, &xecfg);
+		if (xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
+				  &xpp, &xecfg))
+			die("unable to generate checkdiff for %s", one->path);
 
 		if (data.ws_rule & WS_BLANK_AT_EOF) {
 			struct emit_callback ecbdata;
@@ -2555,12 +2617,9 @@ static void builtin_checkdiff(const char *name_a, const char *name_b,
 
 struct diff_filespec *alloc_filespec(const char *path)
 {
-	int namelen = strlen(path);
-	struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
+	struct diff_filespec *spec;
 
-	memset(spec, 0, sizeof(*spec));
-	spec->path = (char *)(spec + 1);
-	memcpy(spec->path, path, namelen+1);
+	FLEXPTR_ALLOC_STR(spec, path, path);
 	spec->count = 1;
 	spec->is_binary = -1;
 	return spec;
@@ -2655,21 +2714,21 @@ static int reuse_worktree_file(const char *name, const unsigned char *sha1, int
 
 static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
 {
-	int len;
-	char *data = xmalloc(100), *dirty = "";
+	struct strbuf buf = STRBUF_INIT;
+	char *dirty = "";
 
 	/* Are we looking at the work tree? */
 	if (s->dirty_submodule)
 		dirty = "-dirty";
 
-	len = snprintf(data, 100,
-		       "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
-	s->data = data;
-	s->size = len;
-	s->should_free = 1;
+	strbuf_addf(&buf, "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
+	s->size = buf.len;
 	if (size_only) {
 		s->data = NULL;
-		free(data);
+		strbuf_release(&buf);
+	} else {
+		s->data = strbuf_detach(&buf, NULL);
+		s->should_free = 1;
 	}
 	return 0;
 }
@@ -2817,8 +2876,7 @@ static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
 	strbuf_addstr(&template, "XXXXXX_");
 	strbuf_addstr(&template, base);
 
-	fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
-			strlen(base) + 1);
+	fd = mks_tempfile_ts(&temp->tempfile, template.buf, strlen(base) + 1);
 	if (fd < 0)
 		die_errno("unable to create temp-file");
 	if (convert_to_working_tree(path,
@@ -2828,11 +2886,10 @@ static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
 	}
 	if (write_in_full(fd, blob, size) != size)
 		die_errno("unable to write temp-file");
-	close(fd);
-	temp->name = temp->tmp_path;
-	strcpy(temp->hex, sha1_to_hex(sha1));
-	temp->hex[40] = 0;
-	sprintf(temp->mode, "%06o", mode);
+	close_tempfile(&temp->tempfile);
+	temp->name = get_tempfile_path(&temp->tempfile);
+	sha1_to_hex_r(temp->hex, sha1);
+	xsnprintf(temp->mode, sizeof(temp->mode), "%06o", mode);
 	strbuf_release(&buf);
 	strbuf_release(&template);
 	free(path_dup);
@@ -2849,17 +2906,11 @@ static struct diff_tempfile *prepare_temp_file(const char *name,
 		 * a '+' entry produces this for file-1.
 		 */
 		temp->name = "/dev/null";
-		strcpy(temp->hex, ".");
-		strcpy(temp->mode, ".");
+		xsnprintf(temp->hex, sizeof(temp->hex), ".");
+		xsnprintf(temp->mode, sizeof(temp->mode), ".");
 		return temp;
 	}
 
-	if (!remove_tempfile_installed) {
-		atexit(remove_tempfile);
-		sigchain_push_common(remove_tempfile_on_signal);
-		remove_tempfile_installed = 1;
-	}
-
 	if (!S_ISGITLINK(one->mode) &&
 	    (!one->sha1_valid ||
 	     reuse_worktree_file(name, one->sha1, 1))) {
@@ -2884,16 +2935,16 @@ 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->sha1_valid)
-				strcpy(temp->hex, sha1_to_hex(null_sha1));
+				sha1_to_hex_r(temp->hex, null_sha1);
 			else
-				strcpy(temp->hex, sha1_to_hex(one->sha1));
+				sha1_to_hex_r(temp->hex, one->sha1);
 			/* 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
 			 * DIFF_FILE_VALID(one).
 			 */
-			sprintf(temp->mode, "%06o", one->mode);
+			xsnprintf(temp->mode, sizeof(temp->mode), "%06o", one->mode);
 		}
 		return temp;
 	}
@@ -3223,6 +3274,7 @@ void diff_setup(struct diff_options *options)
 	options->rename_limit = -1;
 	options->dirstat_permille = diff_dirstat_permille_default;
 	options->context = diff_context_default;
+	options->ws_error_highlight = WSEH_NEW;
 	DIFF_OPT_SET(options, RENAME_EMPTY);
 
 	/* pathchange left =NULL by default */
@@ -3231,6 +3283,8 @@ void diff_setup(struct diff_options *options)
 	options->use_color = diff_use_color_default;
 	options->detect_rename = diff_detect_rename_default;
 	options->xdl_opts |= diff_algorithm;
+	if (diff_compaction_heuristic)
+		DIFF_XDL_SET(options, COMPACTION_HEURISTIC);
 
 	options->orderfile = diff_order_file_cfg;
 
@@ -3609,12 +3663,55 @@ static void enable_patch_output(int *fmt) {
 	*fmt |= DIFF_FORMAT_PATCH;
 }
 
-int diff_opt_parse(struct diff_options *options, const char **av, int ac)
+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(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++;
+	}
+	opt->ws_error_highlight = val;
+	return 1;
+}
+
+int diff_opt_parse(struct diff_options *options,
+		   const char **av, int ac, const char *prefix)
 {
 	const char *arg = av[0];
 	const char *optarg;
 	int argcount;
 
+	if (!prefix)
+		prefix = "";
+
 	/* Output format options */
 	if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch")
 	    || opt_arg(arg, 'U', "unified", &options->context))
@@ -3708,6 +3805,10 @@ int diff_opt_parse(struct diff_options *options, const char **av, int ac)
 		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, "--compaction-heuristic"))
+		DIFF_XDL_SET(options, COMPACTION_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"))
@@ -3739,9 +3840,10 @@ int diff_opt_parse(struct diff_options *options, const char **av, int ac)
 		DIFF_OPT_SET(options, FIND_COPIES_HARDER);
 	else if (!strcmp(arg, "--follow"))
 		DIFF_OPT_SET(options, FOLLOW_RENAMES);
-	else if (!strcmp(arg, "--no-follow"))
+	else if (!strcmp(arg, "--no-follow")) {
 		DIFF_OPT_CLR(options, FOLLOW_RENAMES);
-	else if (!strcmp(arg, "--color"))
+		DIFF_OPT_CLR(options, DEFAULT_FOLLOW_RENAMES);
+	} else if (!strcmp(arg, "--color"))
 		options->use_color = 1;
 	else if (skip_prefix(arg, "--color=", &arg)) {
 		int value = git_config_colorbool(NULL, arg);
@@ -3806,6 +3908,8 @@ int diff_opt_parse(struct diff_options *options, const char **av, int ac)
 		DIFF_OPT_SET(options, SUBMODULE_LOG);
 	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);
 
 	/* misc options */
 	else if (!strcmp(arg, "-z"))
@@ -3828,7 +3932,8 @@ int diff_opt_parse(struct diff_options *options, const char **av, int ac)
 	else if (!strcmp(arg, "--pickaxe-regex"))
 		options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
 	else if ((argcount = short_opt('O', av, &optarg))) {
-		options->orderfile = optarg;
+		const char *path = prefix_filename(prefix, strlen(prefix), optarg);
+		options->orderfile = xstrdup(path);
 		return argcount;
 	}
 	else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
@@ -3867,9 +3972,10 @@ int diff_opt_parse(struct diff_options *options, const char **av, int ac)
 	else if (!strcmp(arg, "--no-function-context"))
 		DIFF_OPT_CLR(options, FUNCCONTEXT);
 	else if ((argcount = parse_long_opt("output", av, &optarg))) {
-		options->file = fopen(optarg, "w");
+		const char *path = prefix_filename(prefix, strlen(prefix), optarg);
+		options->file = fopen(path, "w");
 		if (!options->file)
-			die_errno("Could not open '%s'", optarg);
+			die_errno("Could not open '%s'", path);
 		options->close_file = 1;
 		return argcount;
 	} else
@@ -3996,9 +4102,9 @@ const char *diff_unique_abbrev(const unsigned char *sha1, int len)
 	if (abblen < 37) {
 		static char hex[41];
 		if (len < abblen && abblen <= len + 2)
-			sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
+			xsnprintf(hex, sizeof(hex), "%s%.*s", abbrev, len+3-abblen, "..");
 		else
-			sprintf(hex, "%s...", abbrev);
+			xsnprintf(hex, sizeof(hex), "%s...", abbrev);
 		return hex;
 	}
 	return sha1_to_hex(sha1);
@@ -4425,8 +4531,10 @@ static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
 		xpp.flags = 0;
 		xecfg.ctxlen = 3;
 		xecfg.flags = 0;
-		xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
-			      &xpp, &xecfg);
+		if (xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
+				  &xpp, &xecfg))
+			return error("unable to generate patch-id diff for %s",
+				     p->one->path);
 	}
 
 	git_SHA1_Final(sha1, &ctx);
@@ -4990,7 +5098,7 @@ size_t fill_textconv(struct userdiff_driver *driver,
 {
 	size_t size;
 
-	if (!driver || !driver->textconv) {
+	if (!driver) {
 		if (!DIFF_FILE_VALID(df)) {
 			*outbuf = "";
 			return 0;
@@ -5001,6 +5109,9 @@ size_t fill_textconv(struct userdiff_driver *driver,
 		return df->size;
 	}
 
+	if (!driver->textconv)
+		die("BUG: fill_textconv called with non-textconv driver");
+
 	if (driver->textconv_cache && df->sha1_valid) {
 		*outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
 					  &size);