Merge branch 'jn/merge-renormalize'

* jn/merge-renormalize:
  merge-recursive --renormalize
  rerere: never renormalize
  rerere: migrate to parse-options API
  t4200 (rerere): modernize style
  ll-merge: let caller decide whether to renormalize
  ll-merge: make flag easier to populate
  Documentation/technical: document ll_merge
  merge-trees: let caller decide whether to renormalize
  merge-trees: push choice to renormalize away from low level
  t6038 (merge.renormalize): check that it can be turned off
  t6038 (merge.renormalize): try checkout -m and cherry-pick
  t6038 (merge.renormalize): style nitpicks
  Don't expand CRLFs when normalizing text during merge
  Try normalizing files to avoid delete/modify conflicts when merging
  Avoid conflicts when merging branches with mixed normalization

Conflicts:
	builtin/rerere.c
	t/t4200-rerere.sh

5 files changed, 64 insertions, 26 deletions

diff --git a/builtin/checkout.c b/builtin/checkout.c
index 7250e5c23c..ff5ac1e0ff 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -154,6 +154,10 @@ static int checkout_merged(int pos, struct checkout *state)
 	read_mmblob(&ours, active_cache[pos+1]->sha1);
 	read_mmblob(&theirs, active_cache[pos+2]->sha1);
 
+	/*
+	 * NEEDSWORK: re-create conflicts from merges with
+	 * merge.renormalize set, too
+	 */
 	status = ll_merge(&result_buf, path, &ancestor, "base",
 			  &ours, "ours", &theirs, "theirs", 0);
 	free(ancestor.ptr);
@@ -437,6 +441,13 @@ static int merge_working_tree(struct checkout_opts *opts,
 			 */
 
 			add_files_to_cache(NULL, NULL, 0);
+			/*
+			 * NEEDSWORK: carrying over local changes
+			 * when branches have different end-of-line
+			 * normalization (or clean+smudge rules) is
+			 * a pain; plumb in an option to set
+			 * o.renormalize?
+			 */
 			init_merge_options(&o);
 			o.verbosity = 0;
 			work = write_tree_from_memory(&o);
diff --git a/builtin/merge-recursive.c b/builtin/merge-recursive.c
index 3d00adbfc7..78b9db76a0 100644
--- a/builtin/merge-recursive.c
+++ b/builtin/merge-recursive.c
@@ -48,6 +48,10 @@ int cmd_merge_recursive(int argc, const char **argv, const char *prefix)
 				o.subtree_shift = "";
 			else if (!prefixcmp(arg+2, "subtree="))
 				o.subtree_shift = arg + 10;
+			else if (!strcmp(arg+2, "renormalize"))
+				o.renormalize = 1;
+			else if (!strcmp(arg+2, "no-renormalize"))
+				o.renormalize = 0;
 			else
 				die("Unknown option %s", arg);
 			continue;
diff --git a/builtin/merge.c b/builtin/merge.c
index 47e705ba9b..da26cd629a 100644
--- a/builtin/merge.c
+++ b/builtin/merge.c
@@ -54,6 +54,7 @@ static size_t use_strategies_nr, use_strategies_alloc;
 static const char **xopts;
 static size_t xopts_nr, xopts_alloc;
 static const char *branch;
+static int option_renormalize;
 static int verbosity;
 static int allow_rerere_auto;
 
@@ -504,6 +505,8 @@ static int git_merge_config(const char *k, const char *v, void *cb)
 		return git_config_string(&pull_octopus, k, v);
 	else if (!strcmp(k, "merge.log") || !strcmp(k, "merge.summary"))
 		option_log = git_config_bool(k, v);
+	else if (!strcmp(k, "merge.renormalize"))
+		option_renormalize = git_config_bool(k, v);
 	return git_diff_ui_config(k, v, cb);
 }
 
@@ -625,6 +628,11 @@ static int try_merge_strategy(const char *strategy, struct commit_list *common,
 		if (!strcmp(strategy, "subtree"))
 			o.subtree_shift = "";
 
+		o.renormalize = option_renormalize;
+
+		/*
+		 * NEEDSWORK: merge with table in builtin/merge-recursive
+		 */
 		for (x = 0; x < xopts_nr; x++) {
 			if (!strcmp(xopts[x], "ours"))
 				o.recursive_variant = MERGE_RECURSIVE_OURS;
@@ -634,6 +642,10 @@ static int try_merge_strategy(const char *strategy, struct commit_list *common,
 				o.subtree_shift = "";
 			else if (!prefixcmp(xopts[x], "subtree="))
 				o.subtree_shift = xopts[x]+8;
+			else if (!strcmp(xopts[x], "renormalize"))
+				o.renormalize = 1;
+			else if (!strcmp(xopts[x], "no-renormalize"))
+				o.renormalize = 0;
 			else
 				die("Unknown option for merge-recursive: -X%s", xopts[x]);
 		}
@@ -818,7 +830,7 @@ static int finish_automerge(struct commit_list *common,
 	return 0;
 }
 
-static int suggest_conflicts(void)
+static int suggest_conflicts(int renormalizing)
 {
 	FILE *fp;
 	int pos;
@@ -1303,5 +1315,5 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
 			"stopped before committing as requested\n");
 		return 0;
 	} else
-		return suggest_conflicts();
+		return suggest_conflicts(option_renormalize);
 }
diff --git a/builtin/rerere.c b/builtin/rerere.c
index 67793fa2c7..642bf35587 100644
--- a/builtin/rerere.c
+++ b/builtin/rerere.c
@@ -1,13 +1,16 @@
 #include "builtin.h"
 #include "cache.h"
 #include "dir.h"
+#include "parse-options.h"
 #include "string-list.h"
 #include "rerere.h"
 #include "xdiff/xdiff.h"
 #include "xdiff-interface.h"
 
-static const char git_rerere_usage[] =
-"git rerere [clear | status | diff | gc]";
+static const char * const rerere_usage[] = {
+	"git rerere [clear | status | diff | gc]",
+	NULL,
+};
 
 /* these values are days */
 static int cutoff_noresolve = 15;
@@ -114,25 +117,26 @@ static int diff_two(const char *file1, const char *label1,
 int cmd_rerere(int argc, const char **argv, const char *prefix)
 {
 	struct string_list merge_rr = STRING_LIST_INIT_DUP;
-	int i, fd, flags = 0;
-
-	if (2 < argc) {
-		if (!strcmp(argv[1], "-h"))
-			usage(git_rerere_usage);
-		if (!strcmp(argv[1], "--rerere-autoupdate"))
-			flags = RERERE_AUTOUPDATE;
-		else if (!strcmp(argv[1], "--no-rerere-autoupdate"))
-			flags = RERERE_NOAUTOUPDATE;
-		if (flags) {
-			argc--;
-			argv++;
-		}
-	}
-	if (argc < 2)
+	int i, fd, autoupdate = -1, flags = 0;
+
+	struct option options[] = {
+		OPT_SET_INT(0, "rerere-autoupdate", &autoupdate,
+			"register clean resolutions in index", 1),
+		OPT_END(),
+	};
+
+	argc = parse_options(argc, argv, prefix, options, rerere_usage, 0);
+
+	if (autoupdate == 1)
+		flags = RERERE_AUTOUPDATE;
+	if (autoupdate == 0)
+		flags = RERERE_NOAUTOUPDATE;
+
+	if (argc < 1)
 		return rerere(flags);
 
-	if (!strcmp(argv[1], "forget")) {
-		const char **pathspec = get_pathspec(prefix, argv + 2);
+	if (!strcmp(argv[0], "forget")) {
+		const char **pathspec = get_pathspec(prefix, argv + 1);
 		return rerere_forget(pathspec);
 	}
 
@@ -140,26 +144,26 @@ int cmd_rerere(int argc, const char **argv, const char *prefix)
 	if (fd < 0)
 		return 0;
 
-	if (!strcmp(argv[1], "clear")) {
+	if (!strcmp(argv[0], "clear")) {
 		for (i = 0; i < merge_rr.nr; i++) {
 			const char *name = (const char *)merge_rr.items[i].util;
 			if (!has_rerere_resolution(name))
 				unlink_rr_item(name);
 		}
 		unlink_or_warn(git_path("MERGE_RR"));
-	} else if (!strcmp(argv[1], "gc"))
+	} else if (!strcmp(argv[0], "gc"))
 		garbage_collect(&merge_rr);
-	else if (!strcmp(argv[1], "status"))
+	else if (!strcmp(argv[0], "status"))
 		for (i = 0; i < merge_rr.nr; i++)
 			printf("%s\n", merge_rr.items[i].string);
-	else if (!strcmp(argv[1], "diff"))
+	else if (!strcmp(argv[0], "diff"))
 		for (i = 0; i < merge_rr.nr; i++) {
 			const char *path = merge_rr.items[i].string;
 			const char *name = (const char *)merge_rr.items[i].util;
 			diff_two(rerere_path(name, "preimage"), path, path, path);
 		}
 	else
-		usage(git_rerere_usage);
+		usage_with_options(rerere_usage, options);
 
 	string_list_clear(&merge_rr, 1);
 	return 0;
diff --git a/builtin/revert.c b/builtin/revert.c
index 5ca81580d3..4b47ace36b 100644
--- a/builtin/revert.c
+++ b/builtin/revert.c
@@ -316,6 +316,13 @@ static int do_recursive_merge(struct commit *base, struct commit *next,
 	index_fd = hold_locked_index(&index_lock, 1);
 
 	read_cache();
+
+	/*
+	 * NEEDSWORK: cherry-picking between branches with
+	 * different end-of-line normalization is a pain;
+	 * plumb in an option to set o.renormalize?
+	 * (or better: arbitrary -X options)
+	 */
 	init_merge_options(&o);
 	o.ancestor = base ? base_label : "(empty tree)";
 	o.branch1 = "HEAD";