support gets-with-limit from ruby 1.9

lib/zip/ioextras.rb

@@ -76,20 +76,34 @@ module IOExtras  #:nodoc:
       retVal
     end
 
-    def gets(aSepString = $/)
+    def gets(aSepString = $/, numberOfBytes = nil)
       @lineno = @lineno.next
-      return read if aSepString.nil?
+
+      if numberOfBytes.respond_to?(:to_int)
+        numberOfBytes = numberOfBytes.to_int
+        aSepString = aSepString.to_str if aSepString
+      elsif aSepString.respond_to?(:to_int)
+        numberOfBytes = aSepString.to_int
+        aSepString = $/
+      else
+        numberOfBytes = nil
+        aSepString = aSepString.to_str if aSepString
+      end
+
+      return read(numberOfBytes) if aSepString.nil?
       aSepString = "#{$/}#{$/}" if aSepString.empty?
 
       bufferIndex = 0
-      while ((matchIndex = @outputBuffer.index(aSepString, bufferIndex)) == nil)
+      overLimit = (numberOfBytes && @outputBuffer.bytesize >= numberOfBytes)
+      while ((matchIndex = @outputBuffer.index(aSepString, bufferIndex)) == nil && !overLimit)
         bufferIndex = [bufferIndex, @outputBuffer.bytesize - aSepString.bytesize].max
         if input_finished?
           return @outputBuffer.empty? ? nil : flush
         end
         @outputBuffer << produce_input
+        overlimit = (numberOfBytes && @outputBuffer.bytesize >= numberOfBytes)
       end
-      sepIndex = matchIndex + aSepString.bytesize
+      sepIndex = [matchIndex + aSepString.bytesize, numberOfBytes || @outputBuffer.bytesize].min
       return @outputBuffer.slice!(0...sepIndex)
     end
 

test/ioextrastest.rb

@@ -40,14 +40,14 @@ class AbstractInputStreamTest < Test::Unit::TestCase
       @readPointer = 0
     end
 
-    def read(charsToRead)
+    def sysread(charsToRead, buf = nil)
       retVal=@contents[@readPointer, charsToRead]
       @readPointer+=charsToRead
       return retVal
     end
 
     def produce_input
-      read(100)
+      sysread(100)
     end
 
     def input_finished?
@@ -87,6 +87,19 @@ class AbstractInputStreamTest < Test::Unit::TestCase
     assert_equal(LONG_LINES[2], io.gets("\r\n"))
   end
 
+  def test_getsWithSepAndIndex
+    io = TestAbstractInputStream.new(LONG_LINES.join)
+    assert_equal('x', io.gets("\r\n", 1))
+    assert_equal('x'*47 + "\r", io.gets("\r\n", 48))
+    assert_equal("\n", io.gets(nil, 1))
+    assert_equal('yy', io.gets(nil, 2))
+  end
+
+  def test_getsWithIndex
+    assert_equal(TEST_LINES[0], @io.gets(100))
+    assert_equal('this', @io.gets(4))
+  end
+
   def test_each_line
     lineNumber=0
     @io.each_line {