1 files changed, 292 insertions, 0 deletions
diff --git a/spec/ruby/library/zlib/gzipreader/ungetc_spec.rb b/spec/ruby/library/zlib/gzipreader/ungetc_spec.rb
new file mode 100644
index 0000000000..2d218e8d19
--- /dev/null
+++ b/spec/ruby/library/zlib/gzipreader/ungetc_spec.rb
@@ -0,0 +1,292 @@
+require File.expand_path('../../../../spec_helper', __FILE__)
+require 'stringio'
+require 'zlib'
+
+describe 'GzipReader#ungetc' do
+  before :each do
+    @data = '12345abcde'
+    @zip = [31, 139, 8, 0, 44, 220, 209, 71, 0, 3, 51, 52, 50, 54, 49, 77,
+            76, 74, 78, 73, 5, 0, 157, 5, 0, 36, 10, 0, 0, 0].pack('C*')
+    @io = StringIO.new @zip
+  end
+
+  describe 'at the start of the stream' do
+    before :each do
+      @gz = Zlib::GzipReader.new(@io, external_encoding: Encoding::UTF_8)
+    end
+
+    describe 'with a single-byte character' do
+      it 'prepends the character to the stream' do
+        @gz.ungetc 'x'
+        @gz.read.should == 'x12345abcde'
+      end
+
+      ruby_bug "#13616", ""..."2.6" do
+        it 'decrements pos' do
+          @gz.ungetc 'x'
+          @gz.pos.should == -1
+        end
+      end
+    end
+
+    describe 'with a multi-byte character' do
+      it 'prepends the character to the stream' do
+        @gz.ungetc 'ŷ'
+        @gz.read.should == 'ŷ12345abcde'
+      end
+
+      ruby_bug "#13616", ""..."2.6" do
+        it 'decrements pos' do
+          @gz.ungetc 'ŷ'
+          @gz.pos.should == -2
+        end
+      end
+    end
+
+    describe 'with a multi-character string' do
+      it 'prepends the characters to the stream' do
+        @gz.ungetc 'xŷž'
+        @gz.read.should == 'xŷž12345abcde'
+      end
+
+      ruby_bug "#13616", ""..."2.6" do
+        it 'decrements pos' do
+          @gz.ungetc 'xŷž'
+          @gz.pos.should == -5
+        end
+      end
+    end
+
+    describe 'with an integer' do
+      it 'prepends the corresponding character to the stream' do
+        @gz.ungetc 0x21
+        @gz.read.should == '!12345abcde'
+      end
+
+      ruby_bug "#13616", ""..."2.6" do
+        it 'decrements pos' do
+          @gz.ungetc 0x21
+          @gz.pos.should == -1
+        end
+      end
+    end
+
+    describe 'with an empty string' do
+      it 'does not prepend anything to the stream' do
+        @gz.ungetc ''
+        @gz.read.should == '12345abcde'
+      end
+
+      it 'does not decrement pos' do
+        @gz.ungetc ''
+        @gz.pos.should == 0
+      end
+    end
+
+    quarantine! do # https://bugs.ruby-lang.org/issues/13675
+      describe 'with nil' do
+        it 'does not prepend anything to the stream' do
+          @gz.ungetc nil
+          @gz.read.should == '12345abcde'
+        end
+
+        it 'does not decrement pos' do
+          @gz.ungetc nil
+          @gz.pos.should == 0
+        end
+      end
+    end
+  end
+
+  describe 'in the middle of the stream' do
+    before :each do
+      @gz = Zlib::GzipReader.new(@io, external_encoding: Encoding::UTF_8)
+      @gz.read 5
+    end
+
+    describe 'with a single-byte character' do
+      it 'inserts the character into the stream' do
+        @gz.ungetc 'x'
+        @gz.read.should == 'xabcde'
+      end
+
+      it 'decrements pos' do
+        @gz.ungetc 'x'
+        @gz.pos.should == 4
+      end
+    end
+
+    describe 'with a multi-byte character' do
+      it 'inserts the character into the stream' do
+        @gz.ungetc 'ŷ'
+        @gz.read.should == 'ŷabcde'
+      end
+
+      it 'decrements pos' do
+        @gz.ungetc 'ŷ'
+        @gz.pos.should == 3
+      end
+    end
+
+    describe 'with a multi-character string' do
+      it 'inserts the characters into the stream' do
+        @gz.ungetc 'xŷž'
+        @gz.read.should == 'xŷžabcde'
+      end
+
+      it 'decrements pos' do
+        @gz.ungetc 'xŷž'
+        @gz.pos.should == 0
+      end
+    end
+
+    describe 'with an integer' do
+      it 'inserts the corresponding character into the stream' do
+        @gz.ungetc 0x21
+        @gz.read.should == '!abcde'
+      end
+
+      it 'decrements pos' do
+        @gz.ungetc 0x21
+        @gz.pos.should == 4
+      end
+    end
+
+    describe 'with an empty string' do
+      it 'does not insert anything into the stream' do
+        @gz.ungetc ''
+        @gz.read.should == 'abcde'
+      end
+
+      it 'does not decrement pos' do
+        @gz.ungetc ''
+        @gz.pos.should == 5
+      end
+    end
+
+    quarantine! do # https://bugs.ruby-lang.org/issues/13675
+      describe 'with nil' do
+        it 'does not insert anything into the stream' do
+          @gz.ungetc nil
+          @gz.read.should == 'abcde'
+        end
+
+        it 'does not decrement pos' do
+          @gz.ungetc nil
+          @gz.pos.should == 5
+        end
+      end
+    end
+  end
+
+  describe 'at the end of the stream' do
+    before :each do
+      @gz = Zlib::GzipReader.new(@io, external_encoding: Encoding::UTF_8)
+      @gz.read
+    end
+
+    describe 'with a single-byte character' do
+      it 'appends the character to the stream' do
+        @gz.ungetc 'x'
+        @gz.read.should == 'x'
+      end
+
+      it 'decrements pos' do
+        @gz.ungetc 'x'
+        @gz.pos.should == 9
+      end
+
+      it 'makes eof? false' do
+        @gz.ungetc 'x'
+        @gz.eof?.should be_false
+      end
+    end
+
+    describe 'with a multi-byte character' do
+      it 'appends the character to the stream' do
+        @gz.ungetc 'ŷ'
+        @gz.read.should == 'ŷ'
+      end
+
+      it 'decrements pos' do
+        @gz.ungetc 'ŷ'
+        @gz.pos.should == 8
+      end
+
+      it 'makes eof? false' do
+        @gz.ungetc 'ŷ'
+        @gz.eof?.should be_false
+      end
+    end
+
+    describe 'with a multi-character string' do
+      it 'appends the characters to the stream' do
+        @gz.ungetc 'xŷž'
+        @gz.read.should == 'xŷž'
+      end
+
+      it 'decrements pos' do
+        @gz.ungetc 'xŷž'
+        @gz.pos.should == 5
+      end
+
+      it 'makes eof? false' do
+        @gz.ungetc 'xŷž'
+        @gz.eof?.should be_false
+      end
+    end
+
+    describe 'with an integer' do
+      it 'appends the corresponding character to the stream' do
+        @gz.ungetc 0x21
+        @gz.read.should == '!'
+      end
+
+      it 'decrements pos' do
+        @gz.ungetc 0x21
+        @gz.pos.should == 9
+      end
+
+      it 'makes eof? false' do
+        @gz.ungetc 0x21
+        @gz.eof?.should be_false
+      end
+    end
+
+    describe 'with an empty string' do
+      it 'does not append anything to the stream' do
+        @gz.ungetc ''
+        @gz.read.should == ''
+      end
+
+      it 'does not decrement pos' do
+        @gz.ungetc ''
+        @gz.pos.should == 10
+      end
+
+      it 'does not make eof? false' do
+        @gz.ungetc ''
+        @gz.eof?.should be_true
+      end
+    end
+
+    quarantine! do # https://bugs.ruby-lang.org/issues/13675
+      describe 'with nil' do
+        it 'does not append anything to the stream' do
+          @gz.ungetc nil
+          @gz.read.should == ''
+        end
+
+        it 'does not decrement pos' do
+          @gz.ungetc nil
+          @gz.pos.should == 10
+        end
+
+        it 'does not make eof? false' do
+          @gz.ungetc nil
+          @gz.eof?.should be_true
+        end
+      end
+    end
+  end
+end