Accept Finn Bock's patch #102208 to hardcode EINVAL to 22 when errno

can't be imported.  This makes StringIO.py work with Jython.

Also, get rid of the string module by converting to string methods.

Shorten some lines by using augmented assignment where appropriate.

Lib/StringIO.py

@@ -29,8 +29,12 @@
 - There's a simple test set (see end of this file).
 """
 
-import errno
-import string
+try:
+	from errno import EINVAL
+except ImportError:
+	EINVAL = 22
+
+EMPTYSTRING = ''
 
 class StringIO:
 	def __init__(self, buf = ''):
@@ -52,12 +56,12 @@ def seek(self, pos, mode = 0):
 		if self.closed:
 			raise ValueError, "I/O operation on closed file"
 		if self.buflist:
-			self.buf = self.buf + string.joinfields(self.buflist, '')
+			self.buf += EMPTYSTRING.join(self.buflist)
 			self.buflist = []
 		if mode == 1:
-			pos = pos + self.pos
+			pos += self.pos
 		elif mode == 2:
-			pos = pos + self.len
+			pos += self.len
 		self.pos = max(0, pos)
 	def tell(self):
 		if self.closed:
@@ -67,7 +71,7 @@ def read(self, n = -1):
 		if self.closed:
 			raise ValueError, "I/O operation on closed file"
 		if self.buflist:
-			self.buf = self.buf + string.joinfields(self.buflist, '')
+			self.buf += EMPTYSTRING.join(self.buflist)
 			self.buflist = []
 		if n < 0:
 			newpos = self.len
@@ -80,9 +84,9 @@ def readline(self, length=None):
 		if self.closed:
 			raise ValueError, "I/O operation on closed file"
 		if self.buflist:
-			self.buf = self.buf + string.joinfields(self.buflist, '')
+			self.buf += EMPTYSTRING.join(self.buflist)
 			self.buflist = []
-		i = string.find(self.buf, '\n', self.pos)
+		i = self.buf.find('\n', self.pos)
 		if i < 0:
 			newpos = self.len
 		else:
@@ -110,8 +114,7 @@ def truncate(self, size=None):
 		if size is None:
 			size = self.pos
 		elif size < 0:
-			raise IOError(errno.EINVAL,
-                                      "Negative size not allowed")
+			raise IOError(EINVAL, "Negative size not allowed")
 		elif size < self.pos:
 			self.pos = size
 		self.buf = self.getvalue()[:size]
@@ -125,7 +128,7 @@ def write(self, s):
 		newpos = self.pos + len(s)
 		if self.pos < self.len:
 			if self.buflist:
-				self.buf = self.buf + string.joinfields(self.buflist, '')
+				self.buf += EMPTYSTRING.join(self.buflist)
 				self.buflist = []
 			self.buflist = [self.buf[:self.pos], s, self.buf[newpos:]]
 			self.buf = ''
@@ -136,13 +139,13 @@ def write(self, s):
 			self.len = newpos
 		self.pos = newpos
 	def writelines(self, list):
-		self.write(string.joinfields(list, ''))
+		self.write(EMPTYSTRING.join(list))
 	def flush(self):
 		if self.closed:
 			raise ValueError, "I/O operation on closed file"
 	def getvalue(self):
 		if self.buflist:
-			self.buf = self.buf + string.joinfields(self.buflist, '')
+			self.buf += EMPTYSTRING.join(self.buflist)
 			self.buflist = []
 		return self.buf