Fix backporting.

Author: serhiy-storchaka

Lib/test/test_csv.py

@@ -427,8 +427,6 @@ def test_read_quoting(self):
         self._read_test(['1,\0,3,\0,5'], [['1', ',3,', '5']], quotechar='\0')
         self._read_test(['1\\.5,\\.5,.5'], [[1.5, 0.5, 0.5]],
                         quoting=csv.QUOTE_NONNUMERIC, escapechar='\\')
-        self._read_test(['1\\.5,\\.5,"\\.5"'], [[1.5, 0.5, ".5"]],
-                        quoting=csv.QUOTE_STRINGS, escapechar='\\')
 
     def test_read_skipinitialspace(self):
         self._read_test(['no space, space,  spaces,\ttab'],

Modules/_csv.c

@@ -701,6 +701,8 @@ parse_process_char(ReaderObj *self, _csvstate *module_state, Py_UCS4 c)
         }
         else if (c == dialect->escapechar) {
             /* possible escaped character */
+            if (dialect->quoting == QUOTE_NONNUMERIC)
+                self->numeric_field = 1;
             self->state = ESCAPED_CHAR;
         }
         else if (c == ' ' && dialect->skipinitialspace)