4 files changed, 46 insertions, 17 deletions
diff --git a/spec/ruby/core/integer/coerce_spec.rb b/spec/ruby/core/integer/coerce_spec.rb
index 13fe7b3321..f1f3256032 100644
--- a/spec/ruby/core/integer/coerce_spec.rb
+++ b/spec/ruby/core/integer/coerce_spec.rb
@@ -1,5 +1,7 @@
 require_relative '../../spec_helper'
 
+require 'bigdecimal'
+
 describe "Integer#coerce" do
   context "fixnum" do
     describe "when given a Fixnum" do
@@ -89,16 +91,13 @@ describe "Integer#coerce" do
     end
   end
 
-  ruby_version_is ""..."3.4" do
-    require 'bigdecimal'
-    context "bigdecimal" do
-      it "produces Floats" do
-        x, y = 3.coerce(BigDecimal("3.4"))
-        x.class.should == Float
-        x.should == 3.4
-        y.class.should == Float
-        y.should == 3.0
-      end
+  context "bigdecimal" do
+    it "produces Floats" do
+      x, y = 3.coerce(BigDecimal("3.4"))
+      x.class.should == Float
+      x.should == 3.4
+      y.class.should == Float
+      y.should == 3.0
     end
   end
 
diff --git a/spec/ruby/core/module/prepend_spec.rb b/spec/ruby/core/module/prepend_spec.rb
index f80cfbcca1..c90fa9700e 100644
--- a/spec/ruby/core/module/prepend_spec.rb
+++ b/spec/ruby/core/module/prepend_spec.rb
@@ -737,6 +737,39 @@ describe "Module#prepend" do
     klass.ancestors.take(4).should == [klass, submod, mod, Object]
   end
 
+  # https://bugs.ruby-lang.org/issues/17423
+  describe "when module already exists in ancestor chain" do
+    ruby_version_is ""..."3.1" do
+      it "does not modify the ancestor chain" do
+        m = Module.new do; end
+        a = Module.new do; end
+        b = Class.new do; end
+
+        b.include(a)
+        a.prepend(m)
+        b.ancestors.take(4).should == [b, m, a, Object]
+
+        b.prepend(m)
+        b.ancestors.take(4).should == [b, m, a, Object]
+      end
+    end
+
+    ruby_version_is "3.1" do
+      it "modifies the ancestor chain" do
+        m = Module.new do; end
+        a = Module.new do; end
+        b = Class.new do; end
+
+        b.include(a)
+        a.prepend(m)
+        b.ancestors.take(4).should == [b, m, a, Object]
+
+        b.prepend(m)
+        b.ancestors.take(5).should == [m, b, m, a, Object]
+      end
+    end
+  end
+
   describe "called on a module" do
     describe "included into a class"
     it "does not obscure the module's methods from reflective access" do
diff --git a/spec/ruby/core/rational/coerce_spec.rb b/spec/ruby/core/rational/coerce_spec.rb
index 7aea31aea9..9c0f05829b 100644
--- a/spec/ruby/core/rational/coerce_spec.rb
+++ b/spec/ruby/core/rational/coerce_spec.rb
@@ -1,5 +1,4 @@
 require_relative "../../spec_helper"
-
 require_relative '../../shared/rational/coerce'
 
 describe "Rational#coerce" do
diff --git a/spec/ruby/core/time/at_spec.rb b/spec/ruby/core/time/at_spec.rb
index 25056f2011..0459589f01 100644
--- a/spec/ruby/core/time/at_spec.rb
+++ b/spec/ruby/core/time/at_spec.rb
@@ -32,12 +32,10 @@ describe "Time.at" do
       t2.nsec.should == t.nsec
     end
 
-    ruby_version_is ""..."3.4" do
-      describe "passed BigDecimal" do
-        it "doesn't round input value" do
-          require 'bigdecimal'
-          Time.at(BigDecimal('1.1')).to_f.should == 1.1
-        end
+    describe "passed BigDecimal" do
+      it "doesn't round input value" do
+        require 'bigdecimal'
+        Time.at(BigDecimal('1.1')).to_f.should == 1.1
       end
     end