9 files changed, 118 insertions, 43 deletions
diff --git a/spec/ruby/core/file/birthtime_spec.rb b/spec/ruby/core/file/birthtime_spec.rb
index ff43aa7cef..f82eaf7cca 100644
--- a/spec/ruby/core/file/birthtime_spec.rb
+++ b/spec/ruby/core/file/birthtime_spec.rb
@@ -1,6 +1,11 @@
 require_relative '../../spec_helper'
 
 platform_is :windows, :darwin, :freebsd, :netbsd, :linux do
+  not_implemented_messages = [
+    "birthtime() function is unimplemented", # unsupported OS/version
+    "birthtime is unimplemented",            # unsupported filesystem
+  ]
+
   describe "File.birthtime" do
     before :each do
       @file = __FILE__
@@ -14,20 +19,20 @@ platform_is :windows, :darwin, :freebsd, :netbsd, :linux do
       File.birthtime(@file)
       File.birthtime(@file).should be_kind_of(Time)
     rescue NotImplementedError => e
-      skip e.message if e.message.start_with?("birthtime() function")
+      e.message.should.start_with?(*not_implemented_messages)
     end
 
     it "accepts an object that has a #to_path method" do
       File.birthtime(@file) # Avoid to failure of mock object with old Kernel and glibc
       File.birthtime(mock_to_path(@file))
     rescue NotImplementedError => e
-      e.message.should.start_with?("birthtime() function")
+      e.message.should.start_with?(*not_implemented_messages)
     end
 
     it "raises an Errno::ENOENT exception if the file is not found" do
       -> { File.birthtime('bogus') }.should raise_error(Errno::ENOENT)
     rescue NotImplementedError => e
-      e.message.should.start_with?("birthtime() function")
+      e.message.should.start_with?(*not_implemented_messages)
     end
   end
 
@@ -45,7 +50,7 @@ platform_is :windows, :darwin, :freebsd, :netbsd, :linux do
       @file.birthtime
       @file.birthtime.should be_kind_of(Time)
     rescue NotImplementedError => e
-      e.message.should.start_with?("birthtime() function")
+      e.message.should.start_with?(*not_implemented_messages)
     end
   end
 end
diff --git a/spec/ruby/core/file/stat/birthtime_spec.rb b/spec/ruby/core/file/stat/birthtime_spec.rb
index 5350a571aa..adecee15b0 100644
--- a/spec/ruby/core/file/stat/birthtime_spec.rb
+++ b/spec/ruby/core/file/stat/birthtime_spec.rb
@@ -3,6 +3,11 @@ require_relative '../../../spec_helper'
 platform_is(:windows, :darwin, :freebsd, :netbsd,
             *ruby_version_is("3.5") { :linux },
            ) do
+  not_implemented_messages = [
+    "birthtime() function is unimplemented", # unsupported OS/version
+    "birthtime is unimplemented",            # unsupported filesystem
+  ]
+
   describe "File::Stat#birthtime" do
     before :each do
       @file = tmp('i_exist')
@@ -18,7 +23,7 @@ platform_is(:windows, :darwin, :freebsd, :netbsd,
       st.birthtime.should be_kind_of(Time)
       st.birthtime.should <= Time.now
     rescue NotImplementedError => e
-      e.message.should.start_with?("birthtime() function")
+      e.message.should.start_with?(*not_implemented_messages)
     end
   end
 end
diff --git a/spec/ruby/core/kernel/caller_locations_spec.rb b/spec/ruby/core/kernel/caller_locations_spec.rb
index aaacd9a910..6074879d59 100644
--- a/spec/ruby/core/kernel/caller_locations_spec.rb
+++ b/spec/ruby/core/kernel/caller_locations_spec.rb
@@ -83,7 +83,7 @@ describe 'Kernel#caller_locations' do
       end
     end
 
-    ruby_version_is "3.4" do
+    ruby_version_is "3.4"..."3.5" do
       it "includes core library methods defined in Ruby" do
         file, line = Kernel.instance_method(:tap).source_location
         file.should.start_with?('<internal:')
@@ -94,5 +94,17 @@ describe 'Kernel#caller_locations' do
         loc.path.should.start_with? "<internal:"
       end
     end
+
+    ruby_version_is "3.5" do
+      it "does not include core library methods defined in Ruby" do
+        file, line = Kernel.instance_method(:tap).source_location
+        file.should.start_with?('<internal:')
+
+        loc = nil
+        tap { loc = caller_locations(1, 1)[0] }
+        loc.label.should == "Kernel#tap"
+        loc.path.should == __FILE__
+      end
+    end
   end
 end
diff --git a/spec/ruby/core/kernel/caller_spec.rb b/spec/ruby/core/kernel/caller_spec.rb
index 33c7929a31..4bf9f7c2c2 100644
--- a/spec/ruby/core/kernel/caller_spec.rb
+++ b/spec/ruby/core/kernel/caller_spec.rb
@@ -84,13 +84,26 @@ describe 'Kernel#caller' do
   end
 
   guard -> { Kernel.instance_method(:tap).source_location } do
-    it "includes core library methods defined in Ruby" do
-      file, line = Kernel.instance_method(:tap).source_location
-      file.should.start_with?('<internal:')
+    ruby_version_is ""..."3.5" do
+      it "includes core library methods defined in Ruby" do
+        file, line = Kernel.instance_method(:tap).source_location
+        file.should.start_with?('<internal:')
+
+        loc = nil
+        tap { loc = caller(1, 1)[0] }
+        loc.should =~ /\A<internal:.*in [`'](?:Kernel#)?tap'\z/
+      end
+    end
+
+    ruby_version_is "3.5" do
+      it "includes core library methods defined in Ruby" do
+        file, line = Kernel.instance_method(:tap).source_location
+        file.should.start_with?('<internal:')
 
-      loc = nil
-      tap { loc = caller(1, 1)[0] }
-      loc.should =~ /\A<internal:.*in [`'](?:Kernel#)?tap'\z/
+        loc = nil
+        tap { loc = caller(1, 1)[0] }
+        loc.should =~ /\A#{ __FILE__ }:.*in [`'](?:Kernel#)?tap'\z/
+      end
     end
   end
 end
diff --git a/spec/ruby/core/kernel/inspect_spec.rb b/spec/ruby/core/kernel/inspect_spec.rb
index 1f9ce834ab..e60f7576c5 100644
--- a/spec/ruby/core/kernel/inspect_spec.rb
+++ b/spec/ruby/core/kernel/inspect_spec.rb
@@ -28,4 +28,34 @@ describe "Kernel#inspect" do
     end
     obj.inspect.should be_kind_of(String)
   end
+
+  ruby_version_is "3.5" do
+    it "calls #instance_variables_to_inspect private method to know which variables to display" do
+      obj = Object.new
+      obj.instance_eval do
+        @host = "localhost"
+        @user = "root"
+        @password = "hunter2"
+      end
+      obj.singleton_class.class_eval do
+        private def instance_variables_to_inspect = %i[@host @user @does_not_exist]
+      end
+
+      inspected = obj.inspect.sub(/^#<Object:0x[0-9a-f]+/, '#<Object:0x00')
+      inspected.should == '#<Object:0x00 @host="localhost", @user="root">'
+
+      obj = Object.new
+      obj.instance_eval do
+        @host = "localhost"
+        @user = "root"
+        @password = "hunter2"
+      end
+      obj.singleton_class.class_eval do
+        private def instance_variables_to_inspect = []
+      end
+
+      inspected = obj.inspect.sub(/^#<Object:0x[0-9a-f]+/, '#<Object:0x00')
+      inspected.should == "#<Object:0x00>"
+    end
+  end
 end
diff --git a/spec/ruby/library/net-http/http/post_spec.rb b/spec/ruby/library/net-http/http/post_spec.rb
index ac020bd6be..cebbee4ff3 100644
--- a/spec/ruby/library/net-http/http/post_spec.rb
+++ b/spec/ruby/library/net-http/http/post_spec.rb
@@ -25,9 +25,11 @@ describe "Net::HTTP.post" do
     response.should be_kind_of(Net::HTTPResponse)
   end
 
-  it "sends Content-Type: application/x-www-form-urlencoded by default" do
-    response = Net::HTTP.post(URI("http://localhost:#{NetHTTPSpecs.port}/request/header"), "test=test")
-    response.body.should include({ "Content-Type" => "application/x-www-form-urlencoded" }.inspect.delete("{}"))
+  ruby_version_is ""..."3.5" do
+    it "sends Content-Type: application/x-www-form-urlencoded by default" do
+      response = Net::HTTP.post(URI("http://localhost:#{NetHTTPSpecs.port}/request/header"), "test=test")
+      response.body.should include({ "Content-Type" => "application/x-www-form-urlencoded" }.inspect.delete("{}"))
+    end
   end
 
   it "does not support HTTP Basic Auth" do
diff --git a/spec/ruby/library/net-http/httpgenericrequest/exec_spec.rb b/spec/ruby/library/net-http/httpgenericrequest/exec_spec.rb
index 7de03d7da0..0912e5a71f 100644
--- a/spec/ruby/library/net-http/httpgenericrequest/exec_spec.rb
+++ b/spec/ruby/library/net-http/httpgenericrequest/exec_spec.rb
@@ -31,18 +31,20 @@ describe "Net::HTTPGenericRequest#exec when passed socket, version, path" do
   end
 
   describe "when a request body is set" do
-    it "sets the 'Content-Type' header to 'application/x-www-form-urlencoded' unless the 'Content-Type' header is supplied" do
-      request = Net::HTTPGenericRequest.new("POST", true, true, "/some/path")
-      request.body = "Some Content"
-
-      request.exec(@buffered_socket, "1.1", "/some/other/path")
-      str = @socket.string
-
-      str.should =~ %r[POST /some/other/path HTTP/1.1\r\n]
-      str.should =~ %r[Accept: \*/\*\r\n]
-      str.should =~ %r[Content-Type: application/x-www-form-urlencoded\r\n]
-      str.should =~ %r[Content-Length: 12\r\n]
-      str[-16..-1].should == "\r\n\r\nSome Content"
+    ruby_version_is ""..."3.5" do
+      it "sets the 'Content-Type' header to 'application/x-www-form-urlencoded' unless the 'Content-Type' header is supplied" do
+        request = Net::HTTPGenericRequest.new("POST", true, true, "/some/path")
+        request.body = "Some Content"
+
+        request.exec(@buffered_socket, "1.1", "/some/other/path")
+        str = @socket.string
+
+        str.should =~ %r[POST /some/other/path HTTP/1.1\r\n]
+        str.should =~ %r[Accept: \*/\*\r\n]
+        str.should =~ %r[Content-Type: application/x-www-form-urlencoded\r\n]
+        str.should =~ %r[Content-Length: 12\r\n]
+        str[-16..-1].should == "\r\n\r\nSome Content"
+      end
     end
 
     it "correctly sets the 'Content-Length' header and includes the body" do
@@ -62,19 +64,21 @@ describe "Net::HTTPGenericRequest#exec when passed socket, version, path" do
   end
 
   describe "when a body stream is set" do
-    it "sets the 'Content-Type' header to 'application/x-www-form-urlencoded' unless the 'Content-Type' header is supplied" do
-      request = Net::HTTPGenericRequest.new("POST", true, true, "/some/path",
-                                            "Content-Length" => "10")
-      request.body_stream = StringIO.new("a" * 20)
-
-      request.exec(@buffered_socket, "1.1", "/some/other/path")
-      str = @socket.string
-
-      str.should =~ %r[POST /some/other/path HTTP/1.1\r\n]
-      str.should =~ %r[Accept: \*/\*\r\n]
-      str.should =~ %r[Content-Type: application/x-www-form-urlencoded\r\n]
-      str.should =~ %r[Content-Length: 10\r\n]
-      str[-24..-1].should == "\r\n\r\naaaaaaaaaaaaaaaaaaaa"
+    ruby_version_is ""..."3.5" do
+      it "sets the 'Content-Type' header to 'application/x-www-form-urlencoded' unless the 'Content-Type' header is supplied" do
+        request = Net::HTTPGenericRequest.new("POST", true, true, "/some/path",
+                                              "Content-Length" => "10")
+        request.body_stream = StringIO.new("a" * 20)
+
+        request.exec(@buffered_socket, "1.1", "/some/other/path")
+        str = @socket.string
+
+        str.should =~ %r[POST /some/other/path HTTP/1.1\r\n]
+        str.should =~ %r[Accept: \*/\*\r\n]
+        str.should =~ %r[Content-Type: application/x-www-form-urlencoded\r\n]
+        str.should =~ %r[Content-Length: 10\r\n]
+        str[-24..-1].should == "\r\n\r\naaaaaaaaaaaaaaaaaaaa"
+      end
     end
 
     it "sends the whole stream, regardless of the 'Content-Length' header" do
diff --git a/spec/ruby/optional/capi/digest_spec.rb b/spec/ruby/optional/capi/digest_spec.rb
index c753733906..65c5ecebb1 100644
--- a/spec/ruby/optional/capi/digest_spec.rb
+++ b/spec/ruby/optional/capi/digest_spec.rb
@@ -1,6 +1,10 @@
 require_relative 'spec_helper'
 
-require 'fiddle'
+begin
+  require 'fiddle'
+rescue LoadError
+  return
+end
 
 load_extension('digest')
 
diff --git a/spec/ruby/optional/capi/string_spec.rb b/spec/ruby/optional/capi/string_spec.rb
index 27f65c872a..be9cb9015f 100644
--- a/spec/ruby/optional/capi/string_spec.rb
+++ b/spec/ruby/optional/capi/string_spec.rb
@@ -1222,7 +1222,7 @@ describe "C-API String function" do
       -> { str.upcase! }.should raise_error(RuntimeError, 'can\'t modify string; temporarily locked')
     end
 
-    ruby_bug "#20998", ""..."3.6" do # TODO: check when Ruby 3.5 is released
+    ruby_version_is "3.5" do
       it "raises FrozenError if string is frozen" do
         str = -"rb_str_locktmp"
         -> { @s.rb_str_locktmp(str) }.should raise_error(FrozenError)
@@ -1246,7 +1246,7 @@ describe "C-API String function" do
       -> { @s.rb_str_unlocktmp(+"test") }.should raise_error(RuntimeError, 'temporal unlocking already unlocked string')
     end
 
-    ruby_bug "#20998", ""..."3.6" do # TODO: check when Ruby 3.5 is released
+    ruby_version_is "3.5" do
       it "raises FrozenError if string is frozen" do
         str = -"rb_str_locktmp"
         -> { @s.rb_str_unlocktmp(str) }.should raise_error(FrozenError)