New feature: when saving a file, keep the eol convention of the

original.  New files are written using the eol convention of the
platform, given by os.linesep.  All files are read and written in
binary mode.

diff --git a/Lib/idlelib/IOBinding.py b/Lib/idlelib/IOBinding.py
index d321d8cb5ac67c7e86237a6b34fe7ef69fc8f233..6f46a60d7846cf1d4661d6d134717a90e9fffc9b 100644 (file)
--- a/Lib/idlelib/IOBinding.py
+++ b/Lib/idlelib/IOBinding.py
@@ -178,6 +178,10 @@ class IOBinding:
             self.text.focus_set()
         return "break"
 
+    eol = r"(\r\n)|\n|\r"  # \r\n (Windows), \n (UNIX), or \r (Mac)
+    eol_re = re.compile(eol)
+    eol_convention = os.linesep # Default
+
     def loadfile(self, filename):
         try:
             # open the file in binary mode so that we can handle
@@ -191,8 +195,10 @@ class IOBinding:
 
         chars = self.decode(chars)
         # We now convert all end-of-lines to '\n's
-        eol = r"(\r\n)|\n|\r"  # \r\n (Windows), \n (UNIX), or \r (Mac)
-        chars = re.compile( eol ).sub( r"\n", chars )
+        firsteol = self.eol_re.search(chars)
+        if firsteol:
+            self.eol_convention = firsteol.group(0)
+            chars = self.eol_re.sub(r"\n", chars)
 
         self.text.delete("1.0", "end")
         self.set_filename(None)
@@ -306,8 +312,10 @@ class IOBinding:
     def writefile(self, filename):
         self.fixlastline()
         chars = self.encode(self.text.get("1.0", "end-1c"))
+        if self.eol_convention != "\n":
+            chars = chars.replace("\n", self.eol_convention)
         try:
-            f = open(filename, "w")
+            f = open(filename, "wb")
             f.write(chars)
             f.close()
             return True