>From 330f6072c3dc614936199f1775679328c5452416 Mon Sep 17 00:00:00 2001
From: Noam Postavsky <npostavs@gmail.com>
Date: Sat, 10 Mar 2018 18:20:45 -0500
Subject: [PATCH v1 1/2] Stop signaling an error when reading "smart quotes" in
 symbols

Revert commits from 2018-01-28 "Fix round tripping of read->print for
symbols with strange quotes", and 2017-07-22 "Signal error for symbol
names with strange quotes (Bug#2967)".
* etc/NEWS: Remove corresponding entries.
* src/character.c (confusable_symbol_character_p):
* test/src/lread-tests.el (lread-tests--old-style-backquotes): Remove.
* src/lread.c (read1): Don't signal error on confusable character.
* src/print.c (print_object): Don't escape confusable characters.
---
 etc/NEWS                |  9 ---------
 src/character.c         | 26 --------------------------
 src/character.h         |  2 --
 src/lread.c             |  7 -------
 src/print.c             |  3 +--
 test/src/lread-tests.el | 17 -----------------
 6 files changed, 1 insertion(+), 63 deletions(-)

diff --git a/etc/NEWS b/etc/NEWS
index daacf49e62..1ca4956c96 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -1073,15 +1073,6 @@ and if the new behavior breaks your code please email
 32252@debbugs.gnu.org.  Because %o and %x can now format signed
 integers, they now support the + and space flags.
 
-** To avoid confusion caused by "smart quotes", the reader signals an
-error when reading Lisp symbols which begin with one of the following
-quotation characters: ‘’‛“”‟〞＂＇.  A symbol beginning with such a
-character can be written by escaping the quotation character with a
-backslash.  For example:
-
-    (read "‘smart") => (invalid-read-syntax "strange quote" "‘")
-    (read "\\‘smart") == (intern "‘smart")
-
 +++
 ** Omitting variables after '&optional' and '&rest' is now allowed.
 For example (defun foo (&optional)) is no longer an error.  This is
diff --git a/src/character.c b/src/character.c
index 0b14e476c1..edaeca0a35 100644
--- a/src/character.c
+++ b/src/character.c
@@ -1056,32 +1056,6 @@ blankp (int c)
   return XFIXNUM (category) == UNICODE_CATEGORY_Zs; /* separator, space */
 }
 
-
-/* Return true for characters that would read as symbol characters,
-   but graphically may be confused with some kind of punctuation.  We
-   require an escaping backslash, when such characters begin a
-   symbol.  */
-bool
-confusable_symbol_character_p (int ch)
-{
-  switch (ch)
-    {
-    case 0x2018: /* LEFT SINGLE QUOTATION MARK */
-    case 0x2019: /* RIGHT SINGLE QUOTATION MARK */
-    case 0x201B: /* SINGLE HIGH-REVERSED-9 QUOTATION MARK */
-    case 0x201C: /* LEFT DOUBLE QUOTATION MARK */
-    case 0x201D: /* RIGHT DOUBLE QUOTATION MARK */
-    case 0x201F: /* DOUBLE HIGH-REVERSED-9 QUOTATION MARK */
-    case 0x301E: /* DOUBLE PRIME QUOTATION MARK */
-    case 0xFF02: /* FULLWIDTH QUOTATION MARK */
-    case 0xFF07: /* FULLWIDTH APOSTROPHE */
-      return true;
-
-    default:
-      return false;
-    }
-}
-
 signed char HEXDIGIT_CONST hexdigit[UCHAR_MAX + 1] =
   {
 #if HEXDIGIT_IS_CONST
diff --git a/src/character.h b/src/character.h
index 5dff85aed4..6d5349e07d 100644
--- a/src/character.h
+++ b/src/character.h
@@ -683,8 +683,6 @@ char_surrogate_p (int c)
 extern bool printablep (int);
 extern bool blankp (int);
 
-extern bool confusable_symbol_character_p (int ch);
-
 /* Return a translation table of id number ID.  */
 #define GET_TRANSLATION_TABLE(id) \
   (XCDR (XVECTOR (Vtranslation_table_vector)->contents[(id)]))
diff --git a/src/lread.c b/src/lread.c
index 73e38d8995..fa3b38c312 100644
--- a/src/lread.c
+++ b/src/lread.c
@@ -3539,13 +3539,6 @@ read1 (Lisp_Object readcharfun, int *pch, bool first_in_list)
 	    if (! NILP (result))
 	      return unbind_to (count, result);
 	  }
-        if (!quoted && multibyte)
-          {
-            int ch = STRING_CHAR ((unsigned char *) read_buffer);
-            if (confusable_symbol_character_p (ch))
-              xsignal2 (Qinvalid_read_syntax, build_string ("strange quote"),
-                        CALLN (Fstring, make_fixnum (ch)));
-          }
 	{
 	  Lisp_Object result;
 	  ptrdiff_t nbytes = p - read_buffer;
diff --git a/src/print.c b/src/print.c
index c0c90bc7e9..c112d806cc 100644
--- a/src/print.c
+++ b/src/print.c
@@ -2049,8 +2049,7 @@ print_object (Lisp_Object obj, Lisp_Object printcharfun, bool escapeflag)
 		    || c == ';' || c == '#' || c == '(' || c == ')'
 		    || c == ',' || c == '.' || c == '`'
 		    || c == '[' || c == ']' || c == '?' || c <= 040
-                    || confusing
-		    || (i == 1 && confusable_symbol_character_p (c)))
+		    || confusing)
 		  {
 		    printchar ('\\', printcharfun);
 		    confusing = false;
diff --git a/test/src/lread-tests.el b/test/src/lread-tests.el
index f19d98320a..0d7cd962bd 100644
--- a/test/src/lread-tests.el
+++ b/test/src/lread-tests.el
@@ -142,23 +142,6 @@ lread-tests--last-message
                            "unescaped character literals "
                            "`?\"', `?(', `?)', `?;', `?[', `?]' detected!")))))
 
-(ert-deftest lread-tests--funny-quote-symbols ()
-  "Check that 'smart quotes' or similar trigger errors in symbol names."
-  (dolist (quote-char
-           '(#x2018 ;; LEFT SINGLE QUOTATION MARK
-             #x2019 ;; RIGHT SINGLE QUOTATION MARK
-             #x201B ;; SINGLE HIGH-REVERSED-9 QUOTATION MARK
-             #x201C ;; LEFT DOUBLE QUOTATION MARK
-             #x201D ;; RIGHT DOUBLE QUOTATION MARK
-             #x201F ;; DOUBLE HIGH-REVERSED-9 QUOTATION MARK
-             #x301E ;; DOUBLE PRIME QUOTATION MARK
-             #xFF02 ;; FULLWIDTH QUOTATION MARK
-             #xFF07 ;; FULLWIDTH APOSTROPHE
-             ))
-    (let ((str (format "%cfoo" quote-char)))
-     (should-error (read str) :type 'invalid-read-syntax)
-     (should (eq (read (concat "\\" str)) (intern str))))))
-
 (ert-deftest lread-test-bug26837 ()
   "Test for https://debbugs.gnu.org/26837 ."
   (let ((load-path (cons
-- 
2.11.0