Optimize _autoenv_authorized_env_file

This uses Zsh directly, instead of calling grep potentially twice for a
missing entry.

autoenv.zsh

@@ -192,30 +192,43 @@ _autoenv_hash_pair() {
 }
 
 
-# Checks for the existence of a hash signature in the auth file
-_autoenv_authorized_pair() {
-  local pair=$1
-  test -f $AUTOENV_AUTH_FILE \
-    && \grep -qF $pair $AUTOENV_AUTH_FILE
-}
-
-
+# Check if a given env_file is authorized.
 _autoenv_authorized_env_file() {
   local env_file=$1
+  local env_file_abs=${env_file:A}
   local ret_pair
-  _autoenv_hash_pair $env_file
-  _autoenv_debug "v2 pair: ${ret_pair}"
-  if ! _autoenv_authorized_pair $ret_pair; then
-    # Fallback for v1 (SHA-1) pairs
-    _autoenv_hash_pair $env_file 1
-    _autoenv_debug "v1 pair: ${ret_pair}"
-    if _autoenv_authorized_pair $ret_pair; then
-      # Upgrade v1 entries to v2
-      _autoenv_authorize $env_file
-    else
+
+  local -a lines
+  if [[ -f $AUTOENV_AUTH_FILE ]]; then
+    lines=( ${(M)"${(f@)"$(< $AUTOENV_AUTH_FILE)"}":#:$env_file_abs:*} )
+  fi
+  if [[ -z $lines ]]; then
     return 1
   fi
+
+  if (( $#lines != 1 )); then
+    echo "zsh-autoenv: found unexpected number ($#lines) of auth entries for $env_file in $AUTOENV_AUTH_FILE." >&2
+    echo $lines
   fi
+  line=${lines[-1]}
+
+  if [[ $line == *:2 ]]; then
+    _autoenv_hash_pair $env_file
+    _autoenv_debug "Checking v2 pair: ${ret_pair}"
+    if [[ $line == $ret_pair ]]; then
+      return
+    fi
+  elif [[ $line == *:1 ]]; then
+    # Fallback for v1 (SHA-1) pairs
+    _autoenv_debug "Checking v1 pair: ${ret_pair}"
+    _autoenv_hash_pair $env_file 1
+    if [[ $line == $ret_pair ]]; then
+      # Upgrade v1 entries to v2
+      _autoenv_authorize $env_file
+      return
+    fi
+  fi
+  return 1
 }
 
 _autoenv_authorize() {

tests/setup.zsh

@@ -29,9 +29,10 @@ fi
 # Add file ($1), version ($2), and optional hash ($3) to authentication file.
 test_autoenv_add_to_env() {
   [[ -d ${AUTOENV_AUTH_FILE:h} ]] || mkdir -p ${AUTOENV_AUTH_FILE:h}
+  _autoenv_deauthorize $1
   {
     local ret_pair
-    _autoenv_hash_pair $1 1 ${2:-} && echo $ret_pair
+    _autoenv_hash_pair $1 2 ${2:-} && echo $ret_pair
   } >>| $AUTOENV_AUTH_FILE
 }