~ chicken-core (chicken-5) e9cf59f8734ebdd0c774c223e574fd95dc022581

commit e9cf59f8734ebdd0c774c223e574fd95dc022581
Author:     felix <felix@call-with-current-continuation.org>
AuthorDate: Sun Dec 23 20:44:51 2018 +0100
Commit:     Peter Bex <peter@more-magic.net>
CommitDate: Sun Jan 20 12:32:23 2019 +0100

    Preserve read/write invariance for symbols prefixed with "#!"
    
    Only #!rest, #!key and #!optional should be written, since they are the
    only symbols of that type recognised by the reader.
    
    Signed-off-by: Evan Hanson <evhan@foldling.org>
    Signed-off-by: Peter Bex <peter@more-magic.net>

diff --git a/NEWS b/NEWS
index a24d7e17..2b5e72dd 100644
--- a/NEWS
+++ b/NEWS
@@ -1,3 +1,10 @@
+5.0.2
+
+- Core libraries
+  - Read-write invariance of special symbols starting with #! other
+    than #!key, #!rest or #!optional is now preserved (#1572).
+
+
 5.0.1
 
 - Type system
diff --git a/library.scm b/library.scm
index 08c437df..6a089955 100644
--- a/library.scm
+++ b/library.scm
@@ -4501,8 +4501,7 @@ EOF
 				       (not (and (fx> len 2)
 						 (eq? (##core#inline "C_subchar" str 1) #\#)
 						 (not (eq? (##core#inline "C_subchar" str 2) #\#)))))
-				  ;; #!rest, #!key etc
-				  (eq? (##core#inline "C_subchar" str 1) #\!))
+				  (member str '("#!rest" "#!key" "#!optional")))
 				 ((specialchar? c) #f)
 				 (else #t) ) )
 			 (let ((c (##core#inline "C_subchar" str i)))
diff --git a/tests/syntax-tests.scm b/tests/syntax-tests.scm
index 663aa40e..bd88ec14 100644
--- a/tests/syntax-tests.scm
+++ b/tests/syntax-tests.scm
@@ -275,7 +275,15 @@
 (t '#!rest (with-input-from-string "#!rest" read))
 (t '#!rest (with-input-from-string "|#!rest|" read))
 (t "#!rest" (with-output-to-string (lambda () (write '#!rest))))
+
+;; Non-special symbols starting with shebang
+(f (with-input-from-string "#!foo" read))
+(t '|#!foo| (with-input-from-string "|#!foo|" read))
+(t "|#!foo|" (with-output-to-string (lambda () (write '|#!foo|))))
+
+;; Namespaced symbols
 (t "foo#bar" (with-output-to-string (lambda () (write 'foo#bar))))
+(t "##foo#bar" (with-output-to-string (lambda () (write '##foo#bar))))
 
 ;; These used to be treated specially, but now they just trigger an
 ;; "invalid sharp-sign read syntax" error.