Make zap_downloadl.py create a usable zap.app on Mac (#35242)

Use the unzip utility on Mac for unzipping instead of zipfile.

In addition to not supporting file modes (which the script already works
around) the zipfile module also doesn't support symlinks. The embedded
frameworks inside zap.app rely on symlinks for the application to work.

scripts/tools/zap/zap_download.py

@@ -23,6 +23,7 @@
 import shutil
 import subprocess
 import sys
+import tempfile
 import zipfile
 from typing import Optional
 
@@ -123,13 +124,22 @@ def _SetupReleaseZap(install_directory: str, zap_version: str):
     logging.info("Fetching: %s", url)
 
     r = requests.get(url, stream=True)
-    z = zipfile.ZipFile(io.BytesIO(r.content))
-
-    logging.info("Data downloaded, extracting ...")
-    # extractall() does not preserve permissions (https://github.com/python/cpython/issues/59999)
-    for entry in z.filelist:
-        path = z.extract(entry, install_directory)
-        os.chmod(path, (entry.external_attr >> 16) & 0o777)
+    if zap_platform == 'mac':
+        # zipfile does not support symlinks (https://github.com/python/cpython/issues/82102),
+        # making a zap.app extracted with it unusable due to embedded frameworks.
+        with tempfile.NamedTemporaryFile(suffix='.zip') as tf:
+            for chunk in r.iter_content(chunk_size=4096):
+                tf.write(chunk)
+            tf.flush()
+            os.makedirs(install_directory, exist_ok=True)
+            _ExecuteProcess(['/usr/bin/unzip', '-oq', tf.name], install_directory)
+    else:
+        z = zipfile.ZipFile(io.BytesIO(r.content))
+        logging.info("Data downloaded, extracting ...")
+        # extractall() does not preserve permissions (https://github.com/python/cpython/issues/59999)
+        for entry in z.filelist:
+            path = z.extract(entry, install_directory)
+            os.chmod(path, (entry.external_attr >> 16) & 0o777)
     logging.info("Done extracting.")