pull --rebase: Avoid spurious conflicts and reapplying unnecessary patches

diff --git a/builtin-read-tree.c b/builtin-read-tree.c
index 9c2d634d6d04c3ce08e1352adcba31b527fc08b1..8bdcab11389e8b4facab355f27f0e1926134b86f 100644 (file)
--- a/builtin-read-tree.c
+++ b/builtin-read-tree.c
@@ -13,6 +13,7 @@
 #include "dir.h"
 #include "builtin.h"
 #include "parse-options.h"
+#include "resolve-undo.h"
 
 static int nr_trees;
 static struct tree *trees[MAX_UNPACK_TREES];
@@ -31,7 +32,7 @@ static int list_tree(unsigned char *sha1)
 }
 
 static const char * const read_tree_usage[] = {
-       "git read-tree [[-m [--trivial] [--aggressive] | --reset | --prefix=<prefix>] [-u [--exclude-per-directory=<gitignore>] | -i]]  [--index-output=<file>] <tree-ish1> [<tree-ish2> [<tree-ish3>]]",
+       "git read-tree [[-m [--trivial] [--aggressive] | --reset | --prefix=<prefix>] [-u [--exclude-per-directory=<gitignore>] | -i]] [--no-sparse-checkout] [--index-output=<file>] <tree-ish1> [<tree-ish2> [<tree-ish3>]]",
        NULL
 };
 
@@ -64,6 +65,34 @@ static int exclude_per_directory_cb(const struct option *opt, const char *arg,
        return 0;
 }
 
+static void debug_stage(const char *label, struct cache_entry *ce,
+                       struct unpack_trees_options *o)
+{
+       printf("%s ", label);
+       if (!ce)
+               printf("(missing)\n");
+       else if (ce == o->df_conflict_entry)
+               printf("(conflict)\n");
+       else
+               printf("%06o #%d %s %.8s\n",
+                      ce->ce_mode, ce_stage(ce), ce->name,
+                      sha1_to_hex(ce->sha1));
+}
+
+static int debug_merge(struct cache_entry **stages, struct unpack_trees_options *o)
+{
+       int i;
+
+       printf("* %d-way merge\n", o->merge_size);
+       debug_stage("index", stages[0], o);
+       for (i = 1; i <= o->merge_size; i++) {
+               char buf[24];
+               sprintf(buf, "ent#%d", i);
+               debug_stage(buf, stages[i], o);
+       }
+       return 0;
+}
+
 static struct lock_file lock_file;
 
 int cmd_read_tree(int argc, const char **argv, const char *unused_prefix)
@@ -98,6 +127,10 @@ int cmd_read_tree(int argc, const char **argv, const char *unused_prefix)
                  PARSE_OPT_NONEG, exclude_per_directory_cb },
                OPT_SET_INT('i', NULL, &opts.index_only,
                            "don't check the working tree after merging", 1),
+               OPT_SET_INT(0, "no-sparse-checkout", &opts.skip_sparse_checkout,
+                           "skip applying sparse checkout filter", 1),
+               OPT_SET_INT(0, "debug-unpack", &opts.debug_unpack,
+                           "debug unpack-trees", 1),
                OPT_END()
        };
 
@@ -108,18 +141,21 @@ int cmd_read_tree(int argc, const char **argv, const char *unused_prefix)
 
        git_config(git_default_config, NULL);
 
-       newfd = hold_locked_index(&lock_file, 1);
-
        argc = parse_options(argc, argv, unused_prefix, read_tree_options,
                             read_tree_usage, 0);
 
-       if (read_cache_unmerged() && (opts.prefix || opts.merge))
-               die("You need to resolve your current index first");
+       newfd = hold_locked_index(&lock_file, 1);
 
        prefix_set = opts.prefix ? 1 : 0;
        if (1 < opts.merge + opts.reset + prefix_set)
                die("Which one? -m, --reset, or --prefix?");
-       stage = opts.merge = (opts.reset || opts.merge || prefix_set);
+
+       if (opts.reset || opts.merge || opts.prefix) {
+               if (read_cache_unmerged() && (opts.prefix || opts.merge))
+                       die("You need to resolve your current index first");
+               stage = opts.merge = 1;
+       }
+       resolve_undo_clear();
 
        for (i = 0; i < argc; i++) {
                const char *arg = argv[i];
@@ -163,6 +199,9 @@ int cmd_read_tree(int argc, const char **argv, const char *unused_prefix)
                        opts.head_idx = 1;
        }
 
+       if (opts.debug_unpack)
+               opts.fn = debug_merge;
+
        cache_tree_free(&active_cache_tree);
        for (i = 0; i < nr_trees; i++) {
                struct tree *tree = trees[i];
@@ -172,6 +211,9 @@ int cmd_read_tree(int argc, const char **argv, const char *unused_prefix)
        if (unpack_trees(nr_trees, t, &opts))
                return 128;
 
+       if (opts.debug_unpack)
+               return 0; /* do not write the index out */
+
        /*
         * When reading only one tree (either the most basic form,
         * "-m ent" or "--reset ent" form), we can obtain a fully