Merge #14960: lint/format-strings: Correctly exclude escaped percent symbols

57281199b8 lint/format-strings: Correctly exclude escaped percent symbols (Luke Dashjr)

Pull request description:

  The current code fails to exclude correctly for patterns like `"%%%X"`

Tree-SHA512: cac6f6fb3f06a9190310cd9764ec31cd7d636f9c831057622f418ae5fd2e1d80927a88f585d18f57b279ac21e81518f714dc1a25155377b9297741a73600461e

test/lint/lint-format-strings.py

@@ -241,12 +241,11 @@ def count_format_specifiers(format_string):
     4
     """
     assert(type(format_string) is str)
+    format_string = format_string.replace('%%', 'X')
     n = 0
     in_specifier = False
     for i, char in enumerate(format_string):
-        if format_string[i - 1:i + 1] == "%%" or format_string[i:i + 2] == "%%":
-            pass
-        elif char == "%":
+        if char == "%":
             in_specifier = True
             n += 1
         elif char in "aAcdeEfFgGinopsuxX":