Fix binary diff updaters for macOS canaries

These broke when the new disk layout was enabled in 4602841f for bug
958976. The updater work done in bug 964023 didn’t properly account for
canaries. dmgdiffer.sh is invoked with a “product_name” parameter which
is either “Google Chrome” or “Google Chrome Canary”. Under both old and
new layouts, the framework embedded in the canary is not renamed, but
ships as “Google Chrome Framework.framework”. This is intentional. But
because that framework directory is now outside the versioned directory,
dmgdiffer.sh needs to be aware of its path, because it defines a
“cut” at the versioned directory. By accidentally using the product_name
to define the name of the framework, dmgdiffer.sh broke for just the
canary channel.

As a solution, for just the purpose of defining the name of the
framework under the new layout, dmgdiffer.sh will use the name “Google
Chrome Framework.framework” for the framework when producing a canary
updater. This was chosen instead of a full-time hard-code of “Google
Chrome Framework.framework” in case anyone else uses dmgdiffer.sh to
produce binary diffs of Chromium-like products. For example,
Chromium.app embeds a framework named “Chromium Framework.framework”,
not “Google Chrome Framework.framework”.

This also has a better way to get the Current symbolic link to appear in
the application dirpatch, and fixes a bug in README generation.

Bug: 964712
Change-Id: I3e0a529b1fad08ac7066fcb79423a1dff5df003e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1619066
Commit-Queue: Robert Sesek <rsesek@chromium.org>
Reviewed-by: Robert Sesek <rsesek@chromium.org>
Auto-Submit: Mark Mentovai <mark@chromium.org>
Cr-Commit-Position: refs/heads/master@{#661217}

chrome/installer/mac/dmgdiffer.sh

@@ -146,15 +146,20 @@ make_patch_fs() {
   readonly KS_VERSION_KEY="KSVersion"
   readonly KS_PRODUCT_KEY="KSProductID"
   readonly KS_CHANNEL_KEY="KSChannelID"
-  readonly VERSIONS_DIR_NEW=\
-"Contents/Frameworks/${product_name} Framework.framework/Versions"
   readonly VERSIONS_DIR_OLD="Contents/Versions"
   readonly BUILD_RE="^[0-9]+\\.[0-9]+\\.([0-9]+)\\.[0-9]+\$"
   readonly MIN_BUILD=434
 
-  local product_url="https://www.google.com/chrome/"
+  local versions_dir_new
+  local product_url
   if [[ "${product_name}" = "Google Chrome Canary" ]]; then
+    versions_dir_new=\
+"Contents/Frameworks/Google Chrome Framework.framework/Versions"
     product_url="https://www.google.com/chrome/canary/"
+  else
+    versions_dir_new=\
+"Contents/Frameworks/${product_name} Framework.framework/Versions"
+    product_url="https://www.google.com/chrome/"
   fi
 
   local old_app_path="${old_fs}/${APP_NAME}"
@@ -237,16 +242,16 @@ make_patch_fs() {
   fi
 
   local old_versioned_dir
-  if [[ -e "${old_app_path}/${VERSIONS_DIR_NEW}" ]]; then
-    old_versioned_dir="${old_app_path}/${VERSIONS_DIR_NEW}/${old_app_version}"
+  if [[ -e "${old_app_path}/${versions_dir_new}" ]]; then
+    old_versioned_dir="${old_app_path}/${versions_dir_new}/${old_app_version}"
   else
     old_versioned_dir="${old_app_path}/${VERSIONS_DIR_OLD}/${old_app_version}"
   fi
 
   local new_versioned_dir
   local layout_new
-  if [[ -e "${new_app_path}/${VERSIONS_DIR_NEW}" ]]; then
-    new_versioned_dir="${new_app_path}/${VERSIONS_DIR_NEW}/${new_app_version}"
+  if [[ -e "${new_app_path}/${versions_dir_new}" ]]; then
+    new_versioned_dir="${new_app_path}/${versions_dir_new}/${new_app_version}"
     layout_new="y"
   else
     new_versioned_dir="${new_app_path}/${VERSIONS_DIR_OLD}/${new_app_version}"
@@ -297,13 +302,12 @@ make_patch_fs() {
   # The only visible contents of the disk image will be a README file that
   # explains the image's purpose.
   local new_app_version_extra="${new_app_version}${name_extra}"
-  cat > "${patch_fs}/README.txt" << __EOF__ ||
+  cat > "${patch_fs}/README.txt" << __EOF__ || \
       (err "could not write README.txt" && exit 13)
 This disk image contains a differential updater that can update
 ${product_name} from version ${old_app_version} to ${new_app_version_extra}.
 
-This image is part of the auto-update system and is not independently
-useful.
+This image is part of the auto-update system and is not independently useful.
 
 To install ${product_name}, please visit ${product_url}.
 __EOF__
@@ -333,13 +337,11 @@ ${version_patch_name}_${old_app_version}_${new_app_version}.dirpatch"
   # but to include an empty Versions directory. The versioned directory was
   # already addressed in the preceding dirpatch.
   if [[ -n "${layout_new}" ]]; then
-    # Transform VERSIONS_DIR_NEW into a regular expression pattern by
-    # backslashing the dot.
-    #
-    # This exclude pattern omits the Current symbolic link, which will be fixed
-    # up after dirdiffer creates this dirpatch.
+    # Transform versions_dir_new and the version into a regular expression
+    # pattern by backslashing the dots.
     export DIRDIFFER_EXCLUDE=\
-"/${APP_NAME_RE}/$(echo "${VERSIONS_DIR_NEW}" | sed -e 's/\./\\./g')/"
+"/${APP_NAME_RE}/$(echo "${versions_dir_new}/${new_app_version}" |
+                       sed -e 's/\./\\./g')"
   else
     # VERSIONS_DIR_OLD doesn't contain anything that a regular expression parser
     # would misinterpret.
@@ -364,14 +366,6 @@ ${version_patch_name}_${old_app_version}_${new_app_version}.dirpatch"
 
   unset DIRDIFFER_EXCLUDE DIRDIFFER_NO_DIFF
 
-  if [[ -n "${layout_new}" ]]; then
-    # The Current symbolic link in the framework's Versions directory was
-    # excluded by DIRDIFFER_EXCLUDE, but its presence is critical.
-    rsync --links --perms --times \
-           "${new_app_path}/${VERSIONS_DIR_NEW}/Current" \
-           "${patch_app_dir}/${VERSIONS_DIR_NEW}/Current"
-  fi
-
   echo "${product_name} ${old_app_version}-${new_app_version_extra} Update"
 }