bootstrap: use shlex.split instead of custom implementation

Author: kiike

src/bootstrap/configure.py

@@ -3,6 +3,7 @@
 # ignore-tidy-linelength
 
 from __future__ import absolute_import, division, print_function
+import shlex
 import sys
 import os
 rust_dir = os.path.dirname(os.path.abspath(__file__))
@@ -300,23 +301,10 @@ def set(key, value, config):
 
     arr = config
 
-    # Split on periods unless the block is quoted.
-    parts = []
-    current_part = ''
-    within_quotes = False
-    for character in key:
-        if character in ['"', '\'']:
-            within_quotes = not within_quotes
-        elif character == '.' and not within_quotes:
-            parts.append(current_part)
-            current_part = ''
-        else:
-            current_part += character
-    else:
-        if current_part:
-            parts.append(current_part)
-    if within_quotes:
-        raise RuntimeError('end quote not found in arguments.')
+    # Split `key` on periods using shell semantics.
+    lexer = shlex.shlex(key, punctuation_chars=True, posix=True)
+    lexer.whitespace = "."
+    parts = list(lexer)
 
     for i, part in enumerate(parts):
         if i == len(parts) - 1: