makeqstrdata: permit longer "compressed" outputs

It is possible for this routine to expand some inputs, and in fact
it does for certan strings in the proposed Korean translation of
CircuitPython (#1858).  I did not determine what the maximum
expansion is -- it's probably modest, like len()/7+2 bytes or
something -- so I tried to just make enc[] an adequate
over-allocation, and then ensured that all the strings in the
proposed ko.po now worked.  The worst actual expansion seems to be a
string that goes from 65 UTF-8-encoded bytes to 68 compressed bytes
(+4.6%).  Only a few out of all strings are reported as
non-compressed.

Author: jepler

py/makeqstrdata.py

@@ -180,7 +180,7 @@ def compress(encoding_table, decompressed):
     if not isinstance(decompressed, bytes):
         raise TypeError()
     values, lengths = encoding_table
-    enc = bytearray(len(decompressed))
+    enc = bytearray(len(decompressed) * 2)
     #print(decompressed)
     #print(lengths)
     current_bit = 7
@@ -227,6 +227,8 @@ def compress(encoding_table, decompressed):
                 current_bit -= 1
     if current_bit != 7:
         current_byte += 1
+    if current_byte > len(decompressed):
+        print("Note: compression increased length", repr(decompressed.decode('utf-8')), len(decompressed), current_byte, file=sys.stderr)
     return enc[:current_byte]
 
 def qstr_escape(qst):