Migrate RUBY_VERSION/RUBY_DESCRIPTION to Git

from Subversion.

This behavior is tentative and not discussed well. The point of
discussion will be just the length of commit hash, and I thought we
should include this kind of change in 2.7.0-preview1 release even before
the length is fixed yet.

Let's discuss that afterwards and fix it later as needed. Naruse
suggested that length=10 is very unlikely to cause conflict, and thus
it's used by email notification and rubyci now. This behavior is in
favor of that for now.

2 files changed, 6 insertions, 17 deletions

diff --git a/tool/file2lastrev.rb b/tool/file2lastrev.rb
index 8d68da9f88..0ee22da712 100755
--- a/tool/file2lastrev.rb
+++ b/tool/file2lastrev.rb
@@ -54,7 +54,7 @@ parser.parse! rescue abort "#{File.basename(Program)}: #{$!}\n#{parser}"
   when :revision_h
     Proc.new {|last, changed, modified, branch, title|
       [
-        "#define RUBY_REVISION #{changed || 0}",
+        "#define RUBY_REVISION \"#{changed[0...10]}\"",
         if branch
           e = '..'
           limit = 16
diff --git a/tool/vcs.rb b/tool/vcs.rb
index b97334ecfb..d63336ae60 100644
--- a/tool/vcs.rb
+++ b/tool/vcs.rb
@@ -374,27 +374,16 @@ class VCS
 
     def self.get_revisions(path, srcdir = nil)
       gitcmd = [COMMAND]
-      desc = cmd_read_at(srcdir, [gitcmd + %w[describe --tags --match REV_*]])
-      if /\AREV_(\d+)(?:-(\d+)-g\h+)?\Z/ =~ desc
-        last = ($1.to_i + $2.to_i).to_s
-      end
-      logcmd = gitcmd + %W[log -n1 --date=iso]
-      logcmd << "--grep=^ *git-svn-id: .*@[0-9][0-9]*" unless last
-      idpat = /git-svn-id: .*?@(\d+) \S+\Z/
-      log = cmd_read_at(srcdir, [logcmd])
-      commit = log[/\Acommit (\w+)/, 1]
-      last ||= log[idpat, 1]
+      last = cmd_read_at(srcdir, [[*gitcmd, 'rev-parse', 'HEAD']]).rstrip
       if path
-        cmd = logcmd
-        cmd += [path] unless path == '.'
-        log = cmd_read_at(srcdir, [cmd])
-        changed = log[idpat, 1] || last
+        log = cmd_read_at(srcdir, [[*gitcmd, 'log', '-n1', '--date=iso', path]])
       else
-        changed = last
+        log = cmd_read_at(srcdir, [[*gitcmd, 'log', '-n1', '--date=iso']])
       end
+      changed = log[/\Acommit (\h+)/, 1]
       modified = log[/^Date:\s+(.*)/, 1]
       branch = cmd_read_at(srcdir, [gitcmd + %W[symbolic-ref HEAD]])[%r'\A(?:refs/heads/)?(.+)', 1]
-      title = cmd_read_at(srcdir, [gitcmd + %W[log --format=%s -n1 #{commit}..HEAD]])
+      title = cmd_read_at(srcdir, [gitcmd + %W[log --format=%s -n1 HEAD]])
       title = nil if title.empty?
       [last, changed, modified, branch, title]
     end