Merge branch 'nd/multiple-work-trees'

A replacement for contrib/workdir/git-new-workdir that does not
rely on symbolic links and make sharing of objects and refs safer
by making the borrowee and borrowers aware of each other.

* nd/multiple-work-trees: (41 commits)
  prune --worktrees: fix expire vs worktree existence condition
  t1501: fix test with split index
  t2026: fix broken &&-chain
  t2026 needs procondition SANITY
  git-checkout.txt: a note about multiple checkout support for submodules
  checkout: add --ignore-other-wortrees
  checkout: pass whole struct to parse_branchname_arg instead of individual flags
  git-common-dir: make "modules/" per-working-directory directory
  checkout: do not fail if target is an empty directory
  t2025: add a test to make sure grafts is working from a linked checkout
  checkout: don't require a work tree when checking out into a new one
  git_path(): keep "info/sparse-checkout" per work-tree
  count-objects: report unused files in $GIT_DIR/worktrees/...
  gc: support prune --worktrees
  gc: factor out gc.pruneexpire parsing code
  gc: style change -- no SP before closing parenthesis
  checkout: clean up half-prepared directories in --to mode
  checkout: reject if the branch is already checked out elsewhere
  prune: strategies for linked checkouts
  checkout: support checking out into a new working directory
  ...

1 files changed, 2 insertions, 5 deletions

diff --git a/fast-import.c b/fast-import.c
index e78ca107b3..6378726993 100644
--- a/fast-import.c
+++ b/fast-import.c
@@ -405,7 +405,7 @@ static void dump_marks_helper(FILE *, uintmax_t, struct mark_set *);
 
 static void write_crash_report(const char *err)
 {
-	char *loc = git_path("fast_import_crash_%"PRIuMAX, (uintmax_t) getpid());
+	const char *loc = git_path("fast_import_crash_%"PRIuMAX, (uintmax_t) getpid());
 	FILE *rpt = fopen(loc, "w");
 	struct branch *b;
 	unsigned long lu;
@@ -3113,12 +3113,9 @@ static void parse_progress(void)
 
 static char* make_fast_import_path(const char *path)
 {
-	struct strbuf abs_path = STRBUF_INIT;
-
 	if (!relative_marks_paths || is_absolute_path(path))
 		return xstrdup(path);
-	strbuf_addf(&abs_path, "%s/info/fast-import/%s", get_git_dir(), path);
-	return strbuf_detach(&abs_path, NULL);
+	return xstrdup(git_path("info/fast-import/%s", path));
 }
 
 static void option_import_marks(const char *marks,