tool/sync_default_gems.rb: Accept multiple commit ranges

tool/sync_default_gems.rb

@@ -313,7 +313,7 @@ end
 
 IGNORE_FILE_PATTERN = /\A(?:\.travis.yml|appveyor\.yml|azure-pipelines\.yml|\.git(?:ignore|hub)|Gemfile|README\.md|History\.txt|Rakefile|CODE_OF_CONDUCT\.md)/
 
-def sync_default_gems_with_commits(gem, range)
+def sync_default_gems_with_commits(gem, ranges)
   puts "Sync #{$repositories[gem.to_sym]} with commit history."
 
   IO.popen(%W"git remote") do |f|
@@ -323,13 +323,15 @@ def sync_default_gems_with_commits(gem, range)
   end
   system(*%W"git fetch --no-tags #{gem}")
 
+  commits = ranges.flat_map do |range|
     unless range.include?("..")
       range = "#{range}~1..#{range}"
     end
 
-  commits = IO.popen(%W"git log --format=%H,%s #{range}") do |f|
+    IO.popen(%W"git log --format=%H,%s #{range}") do |f|
       f.read.split("\n").reverse.map{|commit| commit.split(',', 2)}
     end
+  end
 
   # Ignore Merge commit and insufficiency commit for ruby core repository.
   commits.delete_if do |sha, subject|
@@ -467,9 +469,10 @@ when nil, "-h", "--help"
 
   exit
 else
-  if ARGV[1]
-    sync_default_gems_with_commits(ARGV[0], ARGV[1])
+  gem = ARGV.shift
+  if ARGV[0]
+    sync_default_gems_with_commits(gem, ARGV)
   else
-    sync_default_gems(ARGV[0])
+    sync_default_gems(gem)
   end
 end