[rubygems/rubygems] Auto-heal on corrupted lockfile with missing deps

Following up on https://github.com/rubygems/rubygems/pull/6355, which
turned a crash into a nicer error message, this commit auto-heals the
corrupt lockfile instead.

In this particular case (a corrupt Gemfile.lock with missing
dependencies) the LazySpecification will not have accurate dependency
information, we have to materialize the SpecSet to determine there are
missing dependencies. We've already got a way to handle this, via
`SpecSet#incomplete_specs`, but it wasn't quite working for this case
because we'd get to `@incomplete_specs += lookup[name]` and
`lookup[name]` would be empty for the dependency.

With this commit we catch it a bit earlier, marking the parent spec
containing the missing dependency as incomplete.

https://github.com/rubygems/rubygems/commit/486ecb8f20

lib/bundler/installer/parallel_installer.rb

@@ -47,13 +47,6 @@ module Bundler
         dependencies.all? {|d| installed_specs.include? d.name }
       end
 
-      # Check whether spec's dependencies are missing, which can indicate a
-      # corrupted lockfile
-      def dependencies_missing?(all_specs)
-        spec_names = all_specs.map(&:name)
-        dependencies.any? {|d| !spec_names.include? d.name }
-      end
-
       # Represents only the non-development dependencies, the ones that are
       # itself and are in the total list.
       def dependencies
@@ -123,11 +116,7 @@ module Bundler
       unmet_dependencies.each do |spec, unmet_spec_dependencies|
         unmet_spec_dependencies.each do |unmet_spec_dependency|
           found = @specs.find {|s| s.name == unmet_spec_dependency.name && !unmet_spec_dependency.matches_spec?(s.spec) }
-          if found
+          warning << "* #{unmet_spec_dependency}, dependency of #{spec.full_name}, unsatisfied by #{found.full_name}"
-            warning << "* #{unmet_spec_dependency}, dependency of #{spec.full_name}, unsatisfied by #{found.full_name}"
-          else
-            warning << "* #{unmet_spec_dependency}, dependency of #{spec.full_name} but missing from lockfile"
-          end
         end
       end
 
@@ -224,8 +213,6 @@ module Bundler
         if spec.dependencies_installed? @specs
           spec.state = :enqueued
           worker_pool.enq spec
-        elsif spec.dependencies_missing? @specs
-          spec.state = :failed
         end
       end
     end

lib/bundler/spec_set.rb

@@ -24,6 +24,7 @@ module Bundler
 
         name = dep[0].name
         platform = dep[1]
+        incomplete = false
 
         key = [name, platform]
         next if handled.key?(key)
@@ -36,11 +37,14 @@ module Bundler
 
           specs_for_dep.first.dependencies.each do |d|
             next if d.type == :development
+            incomplete = true if d.name != "bundler" && lookup[d.name].empty?
             deps << [d, dep[1]]
           end
-        elsif check
+        else
-          @incomplete_specs += lookup[name]
+          incomplete = true
         end
+
+        @incomplete_specs += lookup[name] if incomplete && check
       end
 
       specs

spec/bundler/lock/lockfile_spec.rb

@@ -1221,7 +1221,7 @@ RSpec.describe "the lockfile format" do
       and include("Either installing with `--full-index` or running `bundle update rack_middleware` should fix the problem.")
   end
 
-  it "errors gracefully on a corrupt lockfile" do
+  it "auto-heals when the lockfile is missing dependent specs" do
     build_repo4 do
       build_gem "minitest-bisect", "1.6.0" do |s|
         s.add_dependency "path_expander", "~> 1.1"
@@ -1253,10 +1253,25 @@ RSpec.describe "the lockfile format" do
     L
 
     cache_gems "minitest-bisect-1.6.0", "path_expander-1.1.1", :gem_repo => gem_repo4
-    bundle :install, :raise_on_error => false
+    bundle :install
 
-    expect(err).not_to include("ERROR REPORT TEMPLATE")
+    expect(lockfile).to eq <<~L
-    expect(err).to include("path_expander (~> 1.1), dependency of minitest-bisect-1.6.0 but missing from lockfile")
+      GEM
+        remote: #{file_uri_for(gem_repo4)}/
+        specs:
+          minitest-bisect (1.6.0)
+            path_expander (~> 1.1)
+          path_expander (1.1.1)
+
+      PLATFORMS
+        #{lockfile_platforms}
+
+      DEPENDENCIES
+        minitest-bisect
+
+      BUNDLED WITH
+         #{Bundler::VERSION}
+    L
   end
 
   it "auto-heals when the lockfile is missing specs" do