4 files changed, 49 insertions, 1 deletions
diff --git a/spec/ruby/core/string/shared/chars.rb b/spec/ruby/core/string/shared/chars.rb
index c730643cf4..74a32fb513 100644
--- a/spec/ruby/core/string/shared/chars.rb
+++ b/spec/ruby/core/string/shared/chars.rb
@@ -14,7 +14,6 @@ describe :string_chars, shared: true do
     s.send(@method){}.should equal(s)
   end
 
-
   it "is unicode aware" do
     "\303\207\342\210\202\303\251\306\222g".send(@method).to_a.should ==
       ["\303\207", "\342\210\202", "\303\251", "\306\222", "g"]
@@ -63,4 +62,25 @@ describe :string_chars, shared: true do
       [0xA2].pack('C').force_encoding('SJIS')
     ]
   end
+
+  it "returns individual chars for dummy encodings" do
+    "ab".dup.force_encoding(Encoding::UTF_7).send(@method).to_a.should == [
+      "\x61".dup.force_encoding(Encoding::UTF_7),
+      "\x62".dup.force_encoding(Encoding::UTF_7)
+    ]
+
+    "abcd".dup.force_encoding(Encoding::UTF_16).send(@method).to_a.should == [
+      "\x61".dup.force_encoding(Encoding::UTF_16),
+      "\x62".dup.force_encoding(Encoding::UTF_16),
+      "\x63".dup.force_encoding(Encoding::UTF_16),
+      "\x64".dup.force_encoding(Encoding::UTF_16)
+    ]
+
+    "abcd".dup.force_encoding(Encoding::UTF_32).send(@method).to_a.should == [
+      "\x61".dup.force_encoding(Encoding::UTF_32),
+      "\x62".dup.force_encoding(Encoding::UTF_32),
+      "\x63".dup.force_encoding(Encoding::UTF_32),
+      "\x64".dup.force_encoding(Encoding::UTF_32)
+    ]
+  end
 end
diff --git a/spec/ruby/core/string/shared/codepoints.rb b/spec/ruby/core/string/shared/codepoints.rb
index 1c28ba3d5e..ecdf7d719d 100644
--- a/spec/ruby/core/string/shared/codepoints.rb
+++ b/spec/ruby/core/string/shared/codepoints.rb
@@ -59,4 +59,9 @@ describe :string_codepoints, shared: true do
     s.ascii_only?.should be_true
     s.send(@method).to_a.should == s.bytes.to_a
   end
+
+  it "returns individual bytes for dummy encodings UTF-16 and UTF-32" do
+    "abcd".dup.force_encoding(Encoding::UTF_16).send(@method).to_a.should == [97, 98, 99, 100]
+    "abcd".dup.force_encoding(Encoding::UTF_32).send(@method).to_a.should == [97, 98, 99, 100]
+  end
 end
diff --git a/spec/ruby/core/string/shared/each_line.rb b/spec/ruby/core/string/shared/each_line.rb
index 231a6d9d4f..c2f3abfa80 100644
--- a/spec/ruby/core/string/shared/each_line.rb
+++ b/spec/ruby/core/string/shared/each_line.rb
@@ -159,4 +159,18 @@ describe :string_each_line, shared: true do
       a.should == ["hello\r\n", "world\r\n"]
     end
   end
+
+  it "does not split lines for dummy UTF-16" do
+    "a\nb".encode(Encoding::UTF_16).lines.should == [
+      "\xFE\xFF\x00\x61\x00\n\x00\x62".dup.force_encoding(Encoding::UTF_16)
+    ]
+
+    str = "\x00\n\n\x00".dup.force_encoding(Encoding::UTF_16)
+    str.lines.should == [str]
+  end
+
+  it "raises Encoding::ConverterNotFoundError for dummy UTF-7" do
+    str = "a\nb".dup.force_encoding(Encoding::UTF_7)
+    -> { str.lines }.should raise_error(Encoding::ConverterNotFoundError)
+  end
 end
diff --git a/spec/ruby/core/string/shared/grapheme_clusters.rb b/spec/ruby/core/string/shared/grapheme_clusters.rb
index 8b666868b1..985b558f08 100644
--- a/spec/ruby/core/string/shared/grapheme_clusters.rb
+++ b/spec/ruby/core/string/shared/grapheme_clusters.rb
@@ -9,6 +9,15 @@ describe :string_grapheme_clusters, shared: true do
     a.should == ['a', 'b', "\u{1f3f3}\u{fe0f}\u{200d}\u{1f308}", "\u{1F43E}"]
   end
 
+  it "returns grapheme clusters for various UTF encodings" do
+    [Encoding::UTF_16LE, Encoding::UTF_16BE, Encoding::UTF_32LE, Encoding::UTF_32BE].each do |enc|
+      a = []
+      # test string: abc[rainbow flag emoji][paw prints]
+      "ab\u{1f3f3}\u{fe0f}\u{200d}\u{1f308}\u{1F43E}".encode(enc).send(@method) { |c| a << c }
+      a.should == ['a', 'b', "\u{1f3f3}\u{fe0f}\u{200d}\u{1f308}", "\u{1F43E}"].map { |s| s.encode(enc) }
+    end
+  end
+
   it "returns self" do
     s = StringSpecs::MyString.new "ab\u{1f3f3}\u{fe0f}\u{200d}\u{1f308}\u{1F43E}"
     s.send(@method) {}.should equal(s)