Bug 1564117 - Part 2: Allow to reimport a specific fdlibm commit. r=arai

This makes it easier to test if modified patch files still apply.

Additionally "--no-backup-if-mismatch" was added to the `patch` command to
avoid generating ".orig" files.

Depends on D37256

Differential Revision: https://phabricator.services.mozilla.com/D37257

--HG--
extra : moz-landing-system : lando

modules/fdlibm/README.mozilla

@@ -9,6 +9,8 @@ resources.
 
 The in-tree copy is updated by running
   sh update.sh
+or
+  sh update.sh <sha-commit>
 from within the modules/fdlibm directory.
 
 Current version: [commit b21ccf63f28a3a4692d8a31419e0a725a1b1a800 (2018-02-14T07:59:30Z)].

modules/fdlibm/import.sh

@@ -2,7 +2,7 @@
 
 set -e
 
-BASE_URL=https://raw.githubusercontent.com/freebsd/freebsd/master/lib/msun/src
+BASE_URL=https://raw.githubusercontent.com/freebsd/freebsd/"${1}"/lib/msun/src
 
 download_source() {
     REMOTE_FILENAME=$1

modules/fdlibm/update.sh

@@ -12,24 +12,23 @@ get_commit() {
         | python -c 'import json, sys; print(json.loads(sys.stdin.read())[0]["sha"])'
 }
 get_date() {
-    curl -s "${API_BASE_URL}/commits?path=lib/msun/src&per_page=1" \
-        | python -c 'import json, sys; print(json.loads(sys.stdin.read())[0]["commit"]["committer"]["date"])'
+    curl -s "${API_BASE_URL}/commits/${COMMIT}" \
+        | python -c 'import json, sys; print(json.loads(sys.stdin.read())["commit"]["committer"]["date"])'
 }
 
 mv ./src/moz.build ./src_moz.build
 rm -rf src
-BEFORE_COMMIT=$(get_commit)
-sh ./import.sh
-mv ./src_moz.build ./src/moz.build
-COMMIT=$(get_commit)
-COMMITDATE=$(get_date)
-if [ ${BEFORE_COMMIT} != ${COMMIT} ]; then
-    echo "Latest commit is changed during import.  Please run again."
-    exit 1
+if [ "$#" -eq 0 ]; then
+    COMMIT=$(get_commit)
+else
+    COMMIT="$1"
 fi
+sh ./import.sh "${COMMIT}"
+mv ./src_moz.build ./src/moz.build
+COMMITDATE=$(get_date)
 for FILE in $(ls patches/*.patch | sort); do
     echo "Applying ${FILE} ..."
-    patch -p3 < ${FILE}
+    patch -p3 --no-backup-if-mismatch < ${FILE}
 done
 hg add src