Issue #18873: The tokenize module, IDLE, 2to3, and the findnocoding.py script

now detect Python source code encoding only in comment lines.

1 files changed, 9 insertions, 7 deletions

diff --git a/Lib/idlelib/IOBinding.py b/Lib/idlelib/IOBinding.py
index 4558ae6..cba8048 100644
--- a/Lib/idlelib/IOBinding.py
+++ b/Lib/idlelib/IOBinding.py
@@ -63,7 +63,7 @@ locale_encoding = locale_encoding.lower()
 encoding = locale_encoding  ### KBK 07Sep07  This is used all over IDLE, check!
                             ### 'encoding' is used below in encode(), check!
 
-coding_re = re.compile("coding[:=]\s*([-\w_.]+)")
+coding_re = re.compile(r'^[ \t\f]*#.*coding[:=][ \t]*([-\w.]+)', re.ASCII)
 
 def coding_spec(data):
     """Return the encoding declaration according to PEP 263.
@@ -84,14 +84,16 @@ def coding_spec(data):
         lines = data
     # consider only the first two lines
     if '\n' in lines:
-        lst = lines.split('\n')[:2]
+        lst = lines.split('\n', 2)[:2]
     elif '\r' in lines:
-        lst = lines.split('\r')[:2]
+        lst = lines.split('\r', 2)[:2]
+    else:
+        lst = [lines]
+    for line in lst:
+        match = coding_re.match(line)
+        if match is not None:
+            break
     else:
-        lst = list(lines)
-    str = '\n'.join(lst)
-    match = coding_re.search(str)
-    if not match:
         return None
     name = match.group(1)
     try: