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 @@ Notes:
 - 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 @@ class StringIO:
 		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 @@ class StringIO:
 		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 @@ class StringIO:
 		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 @@ class StringIO:
 		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 @@ class StringIO:
 		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 @@ class StringIO:
 			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