fix #24558, use same rules for char and string escaping

src/julia-parser.scm

@@ -2179,25 +2179,18 @@
  (begin (read-char (ts:port s)) firstch)
  (let ((b (open-output-string)))
  (let loop ((c firstch))
- (if (eqv? c #\')
- #t
- (begin (if (eqv? c #\")
- (error "invalid character literal") ;; issue 14683
- #t)
+ (if (not (eqv? c #\'))
+ (begin (if (eqv? c #\") ;; issue 14683
+ (error "invalid character literal"))
  (write-char (not-eof-1 c) b)
  (if (eqv? c #\\)
- (write-char
- (not-eof-1 (read-char (ts:port s))) b))
- (loop (read-char (ts:port s))))))
- (let ((str (unescape-string (io.tostring! b))))
- (if (= (length str) 1)
- ;; one byte, e.g. '\xff'. maybe not valid UTF-8, but we
- ;; want to use the raw value as a codepoint in this case.
- (wchar (aref str 0))
- (if (or (not (= (string-length str) 1))
- (not (string.isutf8 str)))
- (error "invalid character literal")
- (string.char str 0))))))))
+ (write-char (not-eof-1 (read-char (ts:port s)))
+ b))
+ (loop (read-char (ts:port s))))))
+ (let ((str (tostr #f b)))
+ (if (= (string-length str) 1)
+ (string.char str 0)
+ (error "invalid character literal")))))))
 
  ;; symbol/expression quote
  ((eq? t ':)

test/syntax.jl

@@ -237,6 +237,12 @@ end
 @test_throws ParseError Meta.parse("'\\A\"'")
 @test Meta.parse("'\"'") == Meta.parse("'\\\"'") == '"' == "\""[1] == '\42'
 
+# issue #24558
+@test_throws ParseError Meta.parse("'\\xff'")
+@test_throws ParseError Meta.parse("'\\x80'")
+@test_throws ParseError Meta.parse("'ab'")
+@test '\u2200' == "\u2200"[1]
+
 @test_throws ParseError Meta.parse("f(2x for x=1:10, y")
 
 # issue #15223