SYNOPSIS
--------
-'git-read-tree' (<tree-ish> | [[-m [--aggressive]| --reset] [-u | -i]] <tree-ish1> [<tree-ish2> [<tree-ish3>]])
+'git-read-tree' (<tree-ish> | [[-m [--aggressive] | --reset | --prefix=<prefix>] [-u | -i]] <tree-ish1> [<tree-ish2> [<tree-ish3>]])
DESCRIPTION
* when both sides adds a path identically. The resolution
is to add that path.
+--prefix=<prefix>/::
+ Keep the current index contents, and read the contents
+ of named tree-ish under directory at `<prefix>`. The
+ original index file cannot have anything at the path
+ `<prefix>` itself, and have nothing in `<prefix>/`
+ directory. Note that the `<prefix>/` value must end
+ with a slash.
+
+
<tree-ish#>::
The id of the tree object(s) to be read/merged.
will complain about unmerged entries if it sees a single entry that is not
stage 0.
- Ok, this all sounds like a collection of totally nonsensical rules,
+ OK, this all sounds like a collection of totally nonsensical rules,
but it's actually exactly what you want in order to do a fast
merge. The different stages represent the "result tree" (stage 0, aka
"merged"), the original tree (stage 1, aka "orig"), and the two trees
- the index file saves and restores with all this information, so you
can merge things incrementally, but as long as it has entries in
- stages 1/2/3 (ie "unmerged entries") you can't write the result. So
+ stages 1/2/3 (i.e., "unmerged entries") you can't write the result. So
now the merge algorithm ends up being really simple:
* you walk the index in order, and ignore all entries of stage 0,
static int aggressive = 0;
static int verbose_update = 0;
static volatile int progress_update = 0;
+static const char *prefix = NULL;
static int head_idx = -1;
static int merge_size = 0;
posns[i] = create_tree_entry_list((struct tree *) posn->item);
posn = posn->next;
}
- if (unpack_trees_rec(posns, len, "", fn, &indpos))
+ if (unpack_trees_rec(posns, len, prefix ? prefix : "",
+ fn, &indpos))
return -1;
}
}
/*
+ * Bind merge.
+ *
+ * Keep the index entries at stage0, collapse stage1 but make sure
+ * stage0 does not have anything there.
+ */
+static int bind_merge(struct cache_entry **src)
+{
+ struct cache_entry *old = src[0];
+ struct cache_entry *a = src[1];
+
+ if (merge_size != 1)
+ return error("Cannot do a bind merge of %d trees\n",
+ merge_size);
+ if (a && old)
+ die("Entry '%s' overlaps. Cannot bind.", a->name);
+ if (!a)
+ return keep_entry(old);
+ else
+ return merged_entry(a, NULL);
+}
+
+/*
* One-way merge.
*
* The rule is:
return error("Cannot do a oneway merge of %d trees",
merge_size);
- if (!a)
+ if (!a) {
+ invalidate_ce_path(old);
return deleted_entry(old, old);
+ }
if (old && same(old, a)) {
if (reset) {
struct stat st;
static int read_cache_unmerged(void)
{
- int i, deleted;
+ int i;
struct cache_entry **dst;
+ struct cache_entry *last = NULL;
read_cache();
dst = active_cache;
- deleted = 0;
for (i = 0; i < active_nr; i++) {
struct cache_entry *ce = active_cache[i];
if (ce_stage(ce)) {
- deleted++;
+ if (last && !strcmp(ce->name, last->name))
+ continue;
invalidate_ce_path(ce);
- continue;
+ last = ce;
+ ce->ce_mode = 0;
+ ce->ce_flags &= ~htons(CE_STAGEMASK);
}
- if (deleted)
- *dst = ce;
- dst++;
+ *dst++ = ce;
}
- active_nr -= deleted;
- return deleted;
+ active_nr = dst - active_cache;
+ return !!last;
}
static void prime_cache_tree_rec(struct cache_tree *it, struct tree *tree)
}
-static const char read_tree_usage[] = "git-read-tree (<sha> | -m [--aggressive] [-u | -i] <sha1> [<sha2> [<sha3>]])";
+static const char read_tree_usage[] = "git-read-tree (<sha> | [[-m [--aggressive] | --reset | --prefix=<prefix>] [-u | -i]] <sha1> [<sha2> [<sha3>]])";
static struct cache_file cache_file;
continue;
}
- /* This differs from "-m" in that we'll silently ignore unmerged entries */
+ /* "--prefix=<subdirectory>/" means keep the current index
+ * entries and put the entries from the tree under the
+ * given subdirectory.
+ */
+ if (!strncmp(arg, "--prefix=", 9)) {
+ if (stage || merge || prefix)
+ usage(read_tree_usage);
+ prefix = arg + 9;
+ merge = 1;
+ stage = 1;
+ if (read_cache_unmerged())
+ die("you need to resolve your current index first");
+ continue;
+ }
+
+ /* This differs from "-m" in that we'll silently ignore
+ * unmerged entries and overwrite working tree files that
+ * correspond to them.
+ */
if (!strcmp(arg, "--reset")) {
- if (stage || merge)
+ if (stage || merge || prefix)
usage(read_tree_usage);
reset = 1;
merge = 1;
/* "-m" stands for "merge", meaning we start in stage 1 */
if (!strcmp(arg, "-m")) {
- if (stage || merge)
+ if (stage || merge || prefix)
usage(read_tree_usage);
if (read_cache_unmerged())
die("you need to resolve your current index first");
if ((update||index_only) && !merge)
usage(read_tree_usage);
+ if (prefix) {
+ int pfxlen = strlen(prefix);
+ int pos;
+ if (prefix[pfxlen-1] != '/')
+ die("prefix must end with /");
+ if (stage != 2)
+ die("binding merge takes only one tree");
+ pos = cache_name_pos(prefix, pfxlen);
+ if (0 <= pos)
+ die("corrupt index file");
+ pos = -pos-1;
+ if (pos < active_nr &&
+ !strncmp(active_cache[pos]->name, prefix, pfxlen))
+ die("subdirectory '%s' already exists.", prefix);
+ pos = cache_name_pos(prefix, pfxlen-1);
+ if (0 <= pos)
+ die("file '%.*s' already exists.", pfxlen-1, prefix);
+ }
+
if (merge) {
if (stage < 2)
die("just how do you expect me to merge %d trees?", stage-1);
switch (stage - 1) {
case 1:
- fn = oneway_merge;
+ fn = prefix ? bind_merge : oneway_merge;
break;
case 2:
fn = twoway_merge;
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