Implement Proc#== and #eql?

Previously, these were not implemented, and Object#== and #eql?
were used.  This tries to check the proc internals to make sure
that procs created from separate blocks are treated as not equal,
but procs created from the same block are treated as equal, even
when the lazy proc allocation optimization is used.

Implements [Feature #14267]

3 files changed, 21 insertions, 9 deletions

diff --git a/spec/ruby/core/proc/eql_spec.rb b/spec/ruby/core/proc/eql_spec.rb
index a3c5a5658d..d95e890c29 100644
--- a/spec/ruby/core/proc/eql_spec.rb
+++ b/spec/ruby/core/proc/eql_spec.rb
@@ -2,5 +2,11 @@ require_relative '../../spec_helper'
 require_relative 'shared/equal'
 
 describe "Proc#eql?" do
-  it_behaves_like :proc_equal_undefined, :eql?
+  ruby_version_is "0"..."2.8" do
+    it_behaves_like :proc_equal_undefined, :eql?
+  end
+
+  ruby_version_is "2.8" do
+    it_behaves_like :proc_equal, :eql?
+  end
 end
diff --git a/spec/ruby/core/proc/equal_value_spec.rb b/spec/ruby/core/proc/equal_value_spec.rb
index 1b6ac792cf..fb465992e9 100644
--- a/spec/ruby/core/proc/equal_value_spec.rb
+++ b/spec/ruby/core/proc/equal_value_spec.rb
@@ -2,5 +2,11 @@ require_relative '../../spec_helper'
 require_relative 'shared/equal'
 
 describe "Proc#==" do
-  it_behaves_like :proc_equal_undefined, :==
+  ruby_version_is "0"..."2.8" do
+    it_behaves_like :proc_equal_undefined, :==
+  end
+
+  ruby_version_is "2.8" do
+    it_behaves_like :proc_equal, :==
+  end
 end
diff --git a/spec/ruby/core/proc/shared/equal.rb b/spec/ruby/core/proc/shared/equal.rb
index 46a1894424..0c0020ca7f 100644
--- a/spec/ruby/core/proc/shared/equal.rb
+++ b/spec/ruby/core/proc/shared/equal.rb
@@ -36,26 +36,26 @@ describe :proc_equal, shared: true do
     a.send(@method, b).should be_false
   end
 
-  it "returns true if both procs have the same body and environment" do
+  it "returns false if procs are distinct but have the same body and environment" do
     p = proc { :foo }
     p2 = proc { :foo }
-    p.send(@method, p2).should be_true
+    p.send(@method, p2).should be_false
   end
 
-  it "returns true if both lambdas with the same body and environment" do
+  it "returns false if lambdas are distinct but have same body and environment" do
     x = -> { :foo }
     x2 = -> { :foo }
-    x.send(@method, x2).should be_true
+    x.send(@method, x2).should be_false
   end
 
-  it "returns true if both different kinds of procs with the same body and env" do
+  it "returns false if using comparing lambda to proc, even with the same body and env" do
     p = -> { :foo }
     p2 = proc { :foo }
-    p.send(@method, p2).should be_true
+    p.send(@method, p2).should be_false
 
     x = proc { :bar }
     x2 = -> { :bar }
-    x.send(@method, x2).should be_true
+    x.send(@method, x2).should be_false
   end
 
   it "returns false if other is not a Proc" do