Fix IndexError when parsing unexpectedly ending quoted-string. (GH-14813)

This exception was caused because the input ended unexpectedly with only one
single quote instead of a pair with some value inside it.
(cherry picked from commit 719a062bcb7b08a56e6576dcd75f4244e6053209)

Co-authored-by: Abhilash Raj <maxking@users.noreply.github.com>

diff --git a/Lib/email/_header_value_parser.py b/Lib/email/_header_value_parser.py
index a342a8e947422a2cb5e1890a5ff0c6093df6817e..801ae728dd1364a67131a88b941a3de447b3d711 100644 (file)
--- a/Lib/email/_header_value_parser.py
+++ b/Lib/email/_header_value_parser.py
@@ -1189,7 +1189,7 @@ def get_bare_quoted_string(value):
             "expected '\"' but found '{}'".format(value))
     bare_quoted_string = BareQuotedString()
     value = value[1:]
-    if value[0] == '"':
+    if value and value[0] == '"':
         token, value = get_qcontent(value)
         bare_quoted_string.append(token)
     while value and value[0] != '"':

diff --git a/Lib/test/test_email/test__header_value_parser.py b/Lib/test/test_email/test__header_value_parser.py
index 55c83efbcd83174e04aca5651d92919918a2ed19..9e862feab10c9e8ae4fcea3d95950bd90ae405f3 100644 (file)
--- a/Lib/test/test_email/test__header_value_parser.py
+++ b/Lib/test/test_email/test__header_value_parser.py
@@ -522,6 +522,10 @@ class TestParser(TestParserMixin, TestEmailBase):
         self._test_get_x(parser.get_bare_quoted_string,
                          '""', '""', '', [], '')
 
+    def test_get_bare_quoted_string_missing_endquotes(self):
+        self._test_get_x(parser.get_bare_quoted_string,
+                         '"', '""', '', [errors.InvalidHeaderDefect], '')
+
     def test_get_bare_quoted_string_following_wsp_preserved(self):
         self._test_get_x(parser.get_bare_quoted_string,
              '"foo"\t bar', '"foo"', 'foo', [], '\t bar')

diff --git a/Misc/NEWS.d/next/Library/2019-07-17-06-54-43.bpo-37491.op0aMs.rst b/Misc/NEWS.d/next/Library/2019-07-17-06-54-43.bpo-37491.op0aMs.rst
new file mode 100644 (file)
index 0000000..af4287b
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2019-07-17-06-54-43.bpo-37491.op0aMs.rst
@@ -0,0 +1,2 @@
+Fix ``IndexError`` when parsing email headers with unexpectedly ending
+bare-quoted string value. Patch by Abhilash Raj.