Merge branch 'master' into lt/apply

* master: (40 commits)
  Clean up sha1 file writing
  Builtin git-cat-file
  builtin format-patch: squelch content-type for 7-bit ASCII
  CMIT_FMT_EMAIL: Q-encode Subject: and display-name part of From: fields.
  add more informative error messages to git-mktag
  remove the artificial restriction tagsize < 8kb
  git-rebase: use canonical A..B syntax to format-patch
  git-format-patch: now built-in.
  fmt-patch: Support --attach
  fmt-patch: understand old <his> notation
  Teach fmt-patch about --keep-subject
  Teach fmt-patch about --numbered
  fmt-patch: implement -o <dir>
  fmt-patch: output file names to stdout
  Teach fmt-patch to write individual files.
  Use RFC2822 dates from "git fmt-patch".
  git-fmt-patch: thinkofix to show [PATCH] properly.
  rename internal format-patch wip
  Minor tweak on subject line in --pretty=email
  Tentative built-in format-patch.
  ...

1 files changed, 105 insertions, 0 deletions

diff --git a/builtin-diff-stages.c b/builtin-diff-stages.c
new file mode 100644
index 0000000000..7c157ca889
--- /dev/null
+++ b/builtin-diff-stages.c
@@ -0,0 +1,105 @@
+/*
+ * Copyright (c) 2005 Junio C Hamano
+ */
+
+#include "cache.h"
+#include "diff.h"
+#include "builtin.h"
+
+static struct diff_options diff_options;
+
+static const char diff_stages_usage[] =
+"git-diff-stages [<common diff options>] <stage1> <stage2> [<path>...]"
+COMMON_DIFF_OPTIONS_HELP;
+
+static void diff_stages(int stage1, int stage2, const char **pathspec)
+{
+	int i = 0;
+	while (i < active_nr) {
+		struct cache_entry *ce, *stages[4] = { NULL, };
+		struct cache_entry *one, *two;
+		const char *name;
+		int len, skip;
+
+		ce = active_cache[i];
+		skip = !ce_path_match(ce, pathspec);
+		len = ce_namelen(ce);
+		name = ce->name;
+		for (;;) {
+			int stage = ce_stage(ce);
+			stages[stage] = ce;
+			if (active_nr <= ++i)
+				break;
+			ce = active_cache[i];
+			if (ce_namelen(ce) != len ||
+			    memcmp(name, ce->name, len))
+				break;
+		}
+		one = stages[stage1];
+		two = stages[stage2];
+
+		if (skip || (!one && !two))
+			continue;
+		if (!one)
+			diff_addremove(&diff_options, '+', ntohl(two->ce_mode),
+				       two->sha1, name, NULL);
+		else if (!two)
+			diff_addremove(&diff_options, '-', ntohl(one->ce_mode),
+				       one->sha1, name, NULL);
+		else if (memcmp(one->sha1, two->sha1, 20) ||
+			 (one->ce_mode != two->ce_mode) ||
+			 diff_options.find_copies_harder)
+			diff_change(&diff_options,
+				    ntohl(one->ce_mode), ntohl(two->ce_mode),
+				    one->sha1, two->sha1, name, NULL);
+	}
+}
+
+int cmd_diff_stages(int ac, const char **av, char **envp)
+{
+	int stage1, stage2;
+	const char *prefix = setup_git_directory();
+	const char **pathspec = NULL;
+
+	git_config(git_diff_config);
+	read_cache();
+	diff_setup(&diff_options);
+	while (1 < ac && av[1][0] == '-') {
+		const char *arg = av[1];
+		if (!strcmp(arg, "-r"))
+			; /* as usual */
+		else {
+			int diff_opt_cnt;
+			diff_opt_cnt = diff_opt_parse(&diff_options,
+						      av+1, ac-1);
+			if (diff_opt_cnt < 0)
+				usage(diff_stages_usage);
+			else if (diff_opt_cnt) {
+				av += diff_opt_cnt;
+				ac -= diff_opt_cnt;
+				continue;
+			}
+			else
+				usage(diff_stages_usage);
+		}
+		ac--; av++;
+	}
+
+	if (ac < 3 ||
+	    sscanf(av[1], "%d", &stage1) != 1 ||
+	    ! (0 <= stage1 && stage1 <= 3) ||
+	    sscanf(av[2], "%d", &stage2) != 1 ||
+	    ! (0 <= stage2 && stage2 <= 3))
+		usage(diff_stages_usage);
+
+	av += 3; /* The rest from av[0] are for paths restriction. */
+	pathspec = get_pathspec(prefix, av);
+
+	if (diff_setup_done(&diff_options) < 0)
+		usage(diff_stages_usage);
+
+	diff_stages(stage1, stage2, pathspec);
+	diffcore_std(&diff_options);
+	diff_flush(&diff_options);
+	return 0;
+}