tools: zlib update by checking latest commit

Refs: nodejs/security-wg#973

tools/dep_updaters/update-zlib.sh

@@ -7,19 +7,19 @@ set -e
 BASE_DIR=$(cd "$(dirname "$0")/../.." && pwd)
 DEPS_DIR="$BASE_DIR/deps"
 
-CURRENT_VERSION=$(grep "#define ZLIB_VERSION" "$DEPS_DIR/zlib/zlib.h" | sed -n "s/^.*VERSION \"\(.*\)\"/\1/p")
+NEW_UPSTREAM_SHA1=$(git ls-remote "https://chromium.googlesource.com/chromium/src/third_party/zlib.git" HEAD | awk '{print $1}')
+NEW_VERSION=$(echo "$NEW_UPSTREAM_SHA1" | head -c 7)
 
-NEW_VERSION_ZLIB_H=$(curl -s "https://chromium.googlesource.com/chromium/src/+/refs/heads/main/third_party/zlib/zlib.h?format=TEXT" | base64 --decode)
+echo "Comparing $NEW_VERSION with current revision"
 
-# Revert zconf.h changes before checking diff 
-perl -i -pe 's|^//#include "chromeconf.h"|#include "chromeconf.h"|' "$DEPS_DIR/zlib/zconf.h"
-git stash -- "$DEPS_DIR/zlib/zconf.h"
+git remote add zlib-upstream https://chromium.googlesource.com/chromium/src/third_party/zlib.git
+git fetch zlib-upstream "$NEW_UPSTREAM_SHA1"
+git remote remove zlib-upstream
 
-git fetch https://chromium.googlesource.com/chromium/src/third_party/zlib.git HEAD
-
-DIFF_TREE=$(git diff --diff-filter=d 'stash@{0}:deps/zlib' FETCH_HEAD)
-
-git stash drop
+# We exclude win32, GN-scraper.py and zlib.gyp from checking diff because they are not part of the zlib source
+DIFF_TREE=$(
+  git diff HEAD:deps/zlib "$NEW_UPSTREAM_SHA1" -- ':!win32' ':!GN-scraper.py' ':!zlib.gyp'
+)
 
 if [ -z "$DIFF_TREE" ]; then
   echo "Skipped because zlib is on the latest version."