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, 1 insertions, 1 deletions

diff --git a/run-command.h b/run-command.h
index 263b9662a..1103805af 100644
--- a/run-command.h
+++ b/run-command.h
@@ -52,7 +52,7 @@ int start_command(struct child_process *);
 int finish_command(struct child_process *);
 int run_command(struct child_process *);
 
-extern char *find_hook(const char *name);
+extern const char *find_hook(const char *name);
 LAST_ARG_MUST_BE_NULL
 extern int run_hook_le(const char *const *env, const char *name, ...);
 extern int run_hook_ve(const char *const *env, const char *name, va_list args);