Merge branch 'jk/no-looking-at-dotgit-outside-repo-final'

This is the endgame of the topic to avoid blindly falling back to
".git" when the setup sequence said we are _not_ in Git repository.
A corner case that happens to work right now may be broken by a
call to die("BUG").

* jk/no-looking-at-dotgit-outside-repo-final:
setup_git_env: avoid blind fall-back to ".git"

diff --combined environment.c
index 2fdba76222b8f5744f1ae84fd11e72a7a3c115cf,6a8e0c2d1b23e67a17158fc995c2acdc4a954c8d..a17d96aa85bd9196da9090c768090aeec8b6b8be
--- 1/environment.c
--- 2/environment.c
+++ b/environment.c
@@@ -16,11 -16,12 +16,11 @@@ int trust_executable_bit = 1
  int trust_ctime = 1;
  int check_stat = 1;
  int has_symlinks = 1;
 -int minimum_abbrev = 4, default_abbrev = 7;
 +int minimum_abbrev = 4, default_abbrev = -1;
  int ignore_case;
  int assume_unchanged;
  int prefer_symlink_refs;
  int is_bare_repository_cfg = -1; /* unspecified */
 -int log_all_ref_updates = -1; /* unspecified */
  int warn_ambiguous_refs = 1;
  int warn_on_object_refname_ambiguity = 1;
  int ref_paranoia = -1;
@@@ -33,7 -34,7 +33,7 @@@ const char *git_attributes_file
  const char *git_hooks_path;
  int zlib_compression_level = Z_BEST_SPEED;
  int core_compression_level;
 -int core_compression_seen;
 +int pack_compression_level = Z_DEFAULT_COMPRESSION;
  int fsync_object_files;
  size_t packed_git_window_size = DEFAULT_PACKED_GIT_WINDOW_SIZE;
  size_t packed_git_limit = DEFAULT_PACKED_GIT_LIMIT;
@@@ -63,7 -64,6 +63,7 @@@ int merge_log_config = -1
  int precomposed_unicode = -1; /* see probe_utf8_pathname_composition() */
  unsigned long pack_size_limit_cfg;
  enum hide_dotfiles_type hide_dotfiles = HIDE_DOTFILES_DOTGITONLY;
 +enum log_refs_config log_all_ref_updates = LOG_REFS_UNSET;
  
  #ifndef PROTECT_HFS_DEFAULT
  #define PROTECT_HFS_DEFAULT 0
@@@ -167,8 -167,11 +167,11 @@@ static void setup_git_env(void
        const char *replace_ref_base;
  
        git_dir = getenv(GIT_DIR_ENVIRONMENT);
-       if (!git_dir)
+       if (!git_dir) {
+               if (!startup_info->have_repository)
+                       die("BUG: setup_git_env called without repository");
                git_dir = DEFAULT_GIT_DIR_ENVIRONMENT;
+       }
        gitfile = read_gitfile(git_dir);
        git_dir = xstrdup(gitfile ? gitfile : git_dir);
        if (get_common_dir(&sb, git_dir))
@@@ -259,7 -262,7 +262,7 @@@ void set_git_work_tree(const char *new_
                return;
        }
        git_work_tree_initialized = 1;
 -      work_tree = xstrdup(real_path(new_work_tree));
 +      work_tree = real_pathdup(new_work_tree, 1);
  }
  
  const char *get_git_work_tree(void)
@@@ -296,16 -299,18 +299,16 @@@ int odb_mkstemp(char *template, size_t 
        return xmkstemp_mode(template, mode);
  }
  
 -int odb_pack_keep(char *name, size_t namesz, const unsigned char *sha1)
 +int odb_pack_keep(const char *name)
  {
        int fd;
  
 -      snprintf(name, namesz, "%s/pack/pack-%s.keep",
 -               get_object_directory(), sha1_to_hex(sha1));
        fd = open(name, O_RDWR|O_CREAT|O_EXCL, 0600);
        if (0 <= fd)
                return fd;
  
        /* slow path */
 -      safe_create_leading_directories(name);
 +      safe_create_leading_directories_const(name);
        return open(name, O_RDWR|O_CREAT|O_EXCL, 0600);
  }