Merge branch 'jc/diff-irreversible-delete'

* jc/diff-irreversible-delete:
  git diff -D: omit the preimage of deletes

1 files changed, 14 insertions, 5 deletions

diff --git a/diff.c b/diff.c
index 56758c7dca..3b40e597d5 100644
--- a/diff.c
+++ b/diff.c
@@ -581,11 +581,14 @@ static void emit_rewrite_diff(const char *name_a,
 		line_prefix, metainfo, a_name.buf, name_a_tab, reset,
 		line_prefix, metainfo, b_name.buf, name_b_tab, reset,
 		line_prefix, fraginfo);
-	print_line_count(o->file, lc_a);
+	if (!o->irreversible_delete)
+		print_line_count(o->file, lc_a);
+	else
+		fprintf(o->file, "?,?");
 	fprintf(o->file, " +");
 	print_line_count(o->file, lc_b);
 	fprintf(o->file, " @@%s\n", reset);
-	if (lc_a)
+	if (lc_a && !o->irreversible_delete)
 		emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
 	if (lc_b)
 		emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
@@ -1981,7 +1984,11 @@ static void builtin_diff(const char *name_a,
 		}
 	}
 
-	if (!DIFF_OPT_TST(o, TEXT) &&
+	if (o->irreversible_delete && lbl[1][0] == '/') {
+		fprintf(o->file, "%s", header.buf);
+		strbuf_reset(&header);
+		goto free_ab_and_return;
+	} else if (!DIFF_OPT_TST(o, TEXT) &&
 	    ( (!textconv_one && diff_filespec_is_binary(one)) ||
 	      (!textconv_two && diff_filespec_is_binary(two)) )) {
 		if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
@@ -2001,8 +2008,7 @@ static void builtin_diff(const char *name_a,
 			fprintf(o->file, "%sBinary files %s and %s differ\n",
 				line_prefix, lbl[0], lbl[1]);
 		o->found_changes = 1;
-	}
-	else {
+	} else {
 		/* Crazy xdl interfaces.. */
 		const char *diffopts = getenv("GIT_DIFF_OPTS");
 		xpparam_t xpp;
@@ -3200,6 +3206,9 @@ int diff_opt_parse(struct diff_options *options, const char **av, int ac)
 			return error("invalid argument to -M: %s", arg+2);
 		options->detect_rename = DIFF_DETECT_RENAME;
 	}
+	else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
+		options->irreversible_delete = 1;
+	}
 	else if (!prefixcmp(arg, "-C") || !prefixcmp(arg, "--find-copies=") ||
 		 !strcmp(arg, "--find-copies")) {
 		if (options->detect_rename == DIFF_DETECT_COPY)