Issue #23681: Fixed Python 2 to 3 poring bugs.
Indexing bytes retiurns an integer, not bytes.
diff --git a/Lib/quopri.py b/Lib/quopri.py
index 46c2a4c..cbd979a 100755
--- a/Lib/quopri.py
+++ b/Lib/quopri.py
@@ -145,7 +145,7 @@
new = new + c; i = i+1
elif i+1 == n and not partial:
partial = 1; break
- elif i+1 < n and line[i+1] == ESCAPE:
+ elif i+1 < n and line[i+1:i+2] == ESCAPE:
new = new + ESCAPE; i = i+2
elif i+2 < n and ishex(line[i+1:i+2]) and ishex(line[i+2:i+3]):
new = new + bytes((unhex(line[i+1:i+3]),)); i = i+3