refactor: Move Flutter-licensed code into third_party (#306)

AUTHORS

@@ -0,0 +1,6 @@
+# This is the list of Shorebird Authors.
+# Names should be added to this file as one of
+#     Organization's name
+#     Individual's name <submission email address>
+#     Individual's name <submission email address> <email2> <emailN>
+Code Town, Inc.

bin/shorebird

@@ -1,45 +1,16 @@
 #!/usr/bin/env bash
-# Copyright 2014 The Flutter Authors. All rights reserved.
-# Use of this source code is governed by a BSD-style license that can be
-# found in the LICENSE file.
-
 set -e
 
-# Needed because if it is set, cd may print the path it changed to.
-unset CDPATH
+# shared.sh expects PROG_NAME, BIN_DIR, and OS to be set.
+# https://gist.github.com/ptc-mrucci/61772387878ed53a6c717d51a21d9371
+# https://stackoverflow.com/questions/59895/how-do-i-get-the-directory-where-a-bash-script-is-located-from-within-the-script/67149152#67149152
 
-# On Mac OS, readlink -f doesn't work, so follow_links traverses the path one
-# link at a time, and then cds into the link destination and find out where it
-# ends up.
-#
-# The returned filesystem path must be a format usable by Dart's URI parser,
-# since the Dart command line tool treats its argument as a file URI, not a
-# filename. For instance, multiple consecutive slashes should be reduced to a
-# single slash, since double-slashes indicate a URI "authority", and these are
-# supposed to be filenames. There is an edge case where this will return
-# multiple slashes: when the input resolves to the root directory. However, if
-# that were the case, we wouldn't be running this shell, so we don't do anything
-# about it.
-#
-# The function is enclosed in a subshell to avoid changing the working directory
-# of the caller.
-function follow_links() (
-  cd -P "$(dirname -- "$1")"
-  file="$PWD/$(basename -- "$1")"
-  while [[ -h "$file" ]]; do
-    cd -P "$(dirname -- "$file")"
-    file="$(readlink -- "$file")"
-    cd -P "$(dirname -- "$file")"
-    file="$PWD/$(basename -- "$file")"
-  done
-  echo "$file"
-)
-
-PROG_NAME="$(follow_links "${BASH_SOURCE[0]}")"
-BIN_DIR="$(cd "${PROG_NAME%/*}" ; pwd -P)"
+BIN_DIR=$(cd "$(dirname "$BASH_SOURCE")"; cd -P "$(dirname "$(readlink "$BASH_SOURCE" || echo .)")"; pwd)
+PROG_NAME="$BIN_DIR/$(basename "$BASH_SOURCE")"
 OS="$(uname -s)"
 
-# To define `shared::execute()` function
-source "$BIN_DIR/internal/shared.sh"
+source "$BIN_DIR/../third_party/flutter/bin/internal/shared.sh"
 
+# We currently depend on a forked (3.7.8 stable) Flutter shared.sh script
+# under third_party. Eventually we'll re-write it ourselves.
 shared::execute "$@"

third_party/README.md

@@ -0,0 +1,3 @@
+This directory contains third-party code that is used by the Shorebird
+project.  This code is not covered under the same licenses as the rest of
+the Shorebird project.

third_party/flutter/LICENSE

@@ -0,0 +1,25 @@
+Copyright 2014 The Flutter Authors. All rights reserved.
+
+Redistribution and use in source and binary forms, with or without modification,
+are permitted provided that the following conditions are met:
+
+    * Redistributions of source code must retain the above copyright
+      notice, this list of conditions and the following disclaimer.
+    * Redistributions in binary form must reproduce the above
+      copyright notice, this list of conditions and the following
+      disclaimer in the documentation and/or other materials provided
+      with the distribution.
+    * Neither the name of Google Inc. nor the names of its
+      contributors may be used to endorse or promote products derived
+      from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

third_party/flutter/README.md

@@ -0,0 +1,2 @@
+This directory contains (modified) copies of files from the Flutter
+project.