Removing the multiple calls to determine VCS type

This removed the subshell from _determine_vcs_base_and_type so it can
set environment variables.

Because this always runs at the beginning of the scripts, there's no
need to do checking if REPOBASE is unset or if VCS_TYPE is not yet
determined, thus I simplified one function and eliminated which_vcs.

Conflicts:
	bin/blackbox_deregister_file

I found this easier to just cherry pick since there was a merge and the
merge was reverted.

bin/_blackbox_common.sh

@@ -23,45 +23,36 @@ source "${0%/*}"/_stack_lib.sh
 : "${EDITOR:=vi}" ;
 
 
-# Outputs a string that is the base directory of this VCS repo.
-# By side-effect, sets the variable VCS_TYPE to either 'git', 'hg',
-# 'svn' or 'unknown'.
-function _determine_vcs_base_and_type() {
-  if git rev-parse --show-toplevel 2>/dev/null ; then
-    VCS_TYPE=git
-  elif [ -d ".svn" ] ; then
-    #find topmost dir with .svn sub-dir
-    parent=""
-    grandparent="."
-    mydir="$(pwd)"
-    while [ -d "$grandparent/.svn" ]; do
-      parent=$grandparent
-      grandparent="$parent/.."
-    done
+# Set REPOBASE to the top of the repository
+# Set VCS_TYPE to 'git', 'hg', 'svn' or 'unknown'
+if git rev-parse --show-toplevel >/dev/null 2>&1 ; then
+  VCS_TYPE=git
+  REPOBASE=$(git rev-parse --show-toplevel)
+elif [ -d ".svn" ] ; then
+  # Find topmost dir with .svn sub-dir
+  parent=""
+  grandparent="."
+  while [ -d "$grandparent/.svn" ]; do
+    parent=$grandparent
+    grandparent="$parent/.."
+  done
 
-    if [ ! -z "$parent" ]; then
-      cd "$parent"
-      pwd
-    else
-      exit 1
-    fi
-    cd "$mydir"
-    VCS_TYPE=svn
-  elif hg root 2>/dev/null ; then
-    # NOTE: hg has to be tested last because it always "succeeds".
-    VCS_TYPE=hg
-  else
-    # We aren't in a repo at all.  Assume the cwd is the root
-    # of the tree.
-    echo .
-    VCS_TYPE=unknown
-  fi
-  export VCS_TYPE
-  # FIXME: Verify this function by checking for .hg or .git
-  # after determining what we believe to be the answer.
-}
+  REPOBASE=$(cd "$parent" ; pwd)
+  VCS_TYPE=svn
+elif hg root >/dev/null 2>&1 ; then
+  # NOTE: hg has to be tested last because it always "succeeds".
+  VCS_TYPE=hg
+  REPOBASE=$(hg root 2>/dev/null)
+else
+  # We aren't in a repo at all.  Assume the cwd is the root
+  # of the tree.
+  VCS_TYPE=unknown
+  REPOBASE="$(pwd)"
+fi
+export VCS_TYPE
+# FIXME: Verify this function by checking for .hg or .git
+# after determining what we believe to be the answer.
 
-REPOBASE=$(_determine_vcs_base_and_type)
 KEYRINGDIR="$REPOBASE/$BLACKBOXDATA"
 BB_ADMINS_FILE="blackbox-admins.txt"
 BB_ADMINS="${KEYRINGDIR}/${BB_ADMINS_FILE}"
@@ -97,7 +88,6 @@ function fail_if_not_exists() {
 
 # Exit we we aren't in a VCS repo.
 function fail_if_not_in_repo() {
-  _determine_vcs_base_and_type
   if [[ $VCS_TYPE = "unknown" ]]; then
     echo "ERROR: This must be run in a VCS repo: git, hg, or svn." >&2
     echo Exiting... >&2
@@ -285,10 +275,6 @@ function enumerate_subdirs() {
 
 # chdir to the base of the repo.
 function change_to_vcs_root() {
-  if [[ $REPOBASE = '' ]]; then
-    echo 'ERROR: _determine_vcs_base_and_type failed to set REPOBASE.'
-    exit 1
-  fi
   cd "$REPOBASE"
 }
 
@@ -351,18 +337,9 @@ function md5sum_file() {
 # Abstract the difference between git and hg:
 #
 
-# Are we in git, hg, or unknown repo?
-function which_vcs() {
-  if [[ $VCS_TYPE = '' ]]; then
-    _determine_vcs_base_and_type >/dev/null
-  fi
-  echo "$VCS_TYPE"
-}
-
-
 # Is this file in the current repo?
 function is_in_vcs() {
-  is_in_$(which_vcs) "$@"
+  is_in_$VCS_TYPE "$@"
 }
 # Mercurial
 function is_in_hg() {
@@ -416,7 +393,7 @@ function is_in_unknown() {
 
 # Add a file to the repo (but don't commit it).
 function vcs_add() {
-  vcs_add_$(which_vcs) "$@"
+  vcs_add_$VCS_TYPE "$@"
 }
 # Mercurial
 function vcs_add_hg() {
@@ -442,7 +419,7 @@ function vcs_add_unknown() {
 
 # Commit a file to the repo
 function vcs_commit() {
-  vcs_commit_$(which_vcs) "$@"
+  vcs_commit_$VCS_TYPE "$@"
 }
 # Mercurial
 function vcs_commit_hg() {
@@ -469,7 +446,7 @@ function vcs_commit_unknown() {
 # Remove file from repo, even if it was deleted locally already.
 # If it doesn't exist yet in the repo, it should be a no-op.
 function vcs_remove() {
-  vcs_remove_$(which_vcs) "$@"
+  vcs_remove_$VCS_TYPE "$@"
 }
 # Mercurial
 function vcs_remove_hg() {
@@ -497,7 +474,7 @@ function vcs_remove_unknown() {
 function vcs_ignore() {
   local file
   for file in "$@"; do
-    vcs_ignore_$(which_vcs) "$file"
+    vcs_ignore_$VCS_TYPE "$file"
   done
 }
 # Mercurial
@@ -538,7 +515,7 @@ function vcs_ignore_generic_file() {
 function vcs_notice() {
   local file
   for file in "$@"; do
-    vcs_notice_$(which_vcs) "$file"
+    vcs_notice_$VCS_TYPE "$file"
   done
 }
 # Mercurial