Fix realpath fallback in rbenv hooks

The symlinks weren't correctly resolved if they were pointing to a
single path component, such as `ln -s foo bar`.

libexec/rbenv-hooks

@@ -35,16 +35,17 @@ resolve_link() {
 }
 
 realpath() {
-  local cwd="$(pwd)"
+  local cwd="$PWD"
   local path="$1"
+  local name
 
   while [ -n "$path" ]; do
-    cd "${path%/*}"
-    local name="${path##*/}"
+    name="${path##*/}"
+    [ "$name" = "$path" ] || cd "${path%/*}"
     path="$(resolve_link "$name" || true)"
   done
 
-  echo "$(pwd)/$name"
+  echo "${PWD}/$name"
   cd "$cwd"
 }
 fi

test/hooks.bats

@@ -59,7 +59,13 @@ OUT
   mkdir -p "$HOME"
   touch "${HOME}/hola.bash"
   ln -s "../../home/hola.bash" "${path}/exec/hello.bash"
+  touch "${path}/exec/bright.sh"
+  ln -s "bright.sh" "${path}/exec/world.bash"
 
   RBENV_HOOK_PATH="$path" run rbenv-hooks exec
-  assert_success "${HOME}/hola.bash"
+  assert_success
+  assert_output <<OUT
+${HOME}/hola.bash
+${RBENV_TEST_DIR}/rbenv.d/exec/bright.sh
+OUT
 }