2 files changed, 39 insertions, 3 deletions
diff --git a/lib/bundler/source/git/git_proxy.rb b/lib/bundler/source/git/git_proxy.rb
index 53a9a78ddf..4922321343 100644
--- a/lib/bundler/source/git/git_proxy.rb
+++ b/lib/bundler/source/git/git_proxy.rb
@@ -118,7 +118,8 @@ module Bundler
             end
           end
 
-          git "fetch", "--force", "--quiet", *extra_fetch_args, :dir => destination if @commit_ref
+          ref = @commit_ref || (full_sha_revision? && @revision)
+          git "fetch", "--force", "--quiet", *extra_fetch_args(ref), :dir => destination if ref
 
           git "reset", "--hard", @revision, :dir => destination
 
@@ -238,6 +239,10 @@ module Bundler
           ref =~ /\A\h{40}\z/
         end
 
+        def full_sha_revision?
+          @revision.match?(/\A\h{40}\z/)
+        end
+
         def git_null(*command, dir: nil)
           check_allowed(command)
 
@@ -399,9 +404,9 @@ module Bundler
           ["--depth", depth.to_s]
         end
 
-        def extra_fetch_args
+        def extra_fetch_args(ref)
           extra_args = [path.to_s, *depth_args]
-          extra_args.push(@commit_ref)
+          extra_args.push(ref)
           extra_args
         end
 
diff --git a/spec/bundler/install/git_spec.rb b/spec/bundler/install/git_spec.rb
index 882f2a2d42..954fd39efe 100644
--- a/spec/bundler/install/git_spec.rb
+++ b/spec/bundler/install/git_spec.rb
@@ -170,5 +170,36 @@ RSpec.describe "bundle install" do
 
       expect(out).to include("Bundle complete!")
     end
+
+    it "allows older revisions of git source when clean true" do
+      build_git "foo", "1.0", :path => lib_path("foo")
+      rev = revision_for(lib_path("foo"))
+
+      bundle "config set path vendor/bundle"
+      bundle "config set clean true"
+      install_gemfile <<-G, :verbose => true
+        source "#{file_uri_for(gem_repo1)}"
+        gem "foo", :git => "#{file_uri_for(lib_path("foo"))}"
+      G
+
+      expect(out).to include("Using foo 1.0 from #{file_uri_for(lib_path("foo"))} (at main@#{rev[0..6]})")
+      expect(the_bundle).to include_gems "foo 1.0", :source => "git@#{lib_path("foo")}"
+
+      old_lockfile = lockfile
+
+      update_git "foo", "2.0", :path => lib_path("foo"), :gemspec => true
+      rev2 = revision_for(lib_path("foo"))
+
+      bundle :update, :all => true, :verbose => true
+      expect(out).to include("Using foo 2.0 (was 1.0) from #{file_uri_for(lib_path("foo"))} (at main@#{rev2[0..6]})")
+      expect(out).to include("Removing foo (#{rev[0..11]})")
+      expect(the_bundle).to include_gems "foo 2.0", :source => "git@#{lib_path("foo")}"
+
+      lockfile(old_lockfile)
+
+      bundle :install, :verbose => true
+      expect(out).to include("Using foo 1.0 from #{file_uri_for(lib_path("foo"))} (at main@#{rev[0..6]})")
+      expect(the_bundle).to include_gems "foo 1.0", :source => "git@#{lib_path("foo")}"
+    end
   end
 end