From ce24f67224686277546f8c7dfd8d5dbabc69a103 Mon Sep 17 00:00:00 2001
From: Alex Shinn <ashinn@users.noreply.github.com>
Date: Mon, 5 May 2014 14:24:52 +0900
Subject: [PATCH] Making #! a line comment only if followed by whitespace or /,
 otherwise we report a bad symbol for anything other than (no-)fold-case.

---
 lib/srfi/38.scm | 25 +++++++++++++++----------
 sexp.c          | 31 ++++++++++++++++++-------------
 2 files changed, 33 insertions(+), 23 deletions(-)

diff --git a/lib/srfi/38.scm b/lib/srfi/38.scm
index bbbb18ad..2b362129 100644
--- a/lib/srfi/38.scm
+++ b/lib/srfi/38.scm
@@ -287,17 +287,22 @@
                 (skip-comment in 0)
                 (read-one))
                ((#\!)
-                (let ((name (read-name #f in)))
+                (read-char in)
+                (let ((c (peek-char in)))
                   (cond
-                   ((string-ci=? name "!fold-case")
-                    (set-port-fold-case! in #t))
-                   ((string-ci=? name "!no-fold-case")
-                    (set-port-fold-case! in #f))
-                   (else ;; assume a #!/bin/bash line
-                    (skip-line in)))
-                  (let ((res (read-one)))
-                    (if (not (eof-object? res))
-                        res))))
+                   ((or (char-whitespace? c) (eqv? c #\/))
+                    (skip-line in)
+                    (read-one))
+                   (else
+                    (let ((name (read-name #f in)))
+                      (cond
+                       ((string-ci=? name "fold-case")
+                        (set-port-fold-case! in #t))
+                       ((string-ci=? name "no-fold-case")
+                        (set-port-fold-case! in #f))
+                       (else            ;; assume a #!/bin/bash line
+                        (error "unknown #! symbol" name)))
+                      (read-one))))))
                ((#\() (list->vector (read-one)))
                ((#\') (read-char in) (list 'syntax (read-one)))
                ((#\`) (read-char in) (list 'quasisyntax (read-one)))
diff --git a/sexp.c b/sexp.c
index 88337d13..30e84d06 100644
--- a/sexp.c
+++ b/sexp.c
@@ -2891,24 +2891,29 @@ sexp sexp_read_raw (sexp ctx, sexp in) {
         goto scan_loop;
       break;
     case '!':
-#if SEXP_USE_FOLD_CASE_SYMS
-      res = sexp_read_symbol(ctx, in, '!', 0);
-      if (sexp_stringp(res)
-          && strcmp("!fold-case", sexp_string_data(res)) == 0) {
-        sexp_port_fold_casep(in) = 1;
-      } else if (sexp_stringp(res)
-                 && strcmp("!no-fold-case", sexp_string_data(res)) == 0) {
-        sexp_port_fold_casep(in) = 0;
-      } else {
-#endif
+      c1 = sexp_read_char(ctx, in);
+      if (isspace(c1) || c1 == '/') {
         while ((c1 = sexp_read_char(ctx, in)) != EOF)
           if (c1 == '\n')
             break;
         sexp_port_line(in)++;
-#if SEXP_USE_FOLD_CASE_SYMS
+        res = SEXP_VOID;
+      } else {
+        sexp_push_char(ctx, c1, in);
+        res = sexp_read_symbol(ctx, in, '!', 0);
+        if (SEXP_USE_FOLD_CASE_SYMS && sexp_stringp(res)
+            && strcmp("!fold-case", sexp_string_data(res)) == 0) {
+          sexp_port_fold_casep(in) = 1;
+        } else if (SEXP_USE_FOLD_CASE_SYMS && sexp_stringp(res)
+                   && strcmp("!no-fold-case", sexp_string_data(res)) == 0) {
+          sexp_port_fold_casep(in) = 0;
+        } else {
+          res = sexp_read_error(ctx, "unknown #! symbol", res, in);
+        }
       }
-#endif
-      goto scan_loop;
+      if (!sexp_exceptionp(res))
+        goto scan_loop;
+      break;
     case '\\':
       c1 = sexp_read_char(ctx, in);
       c2 = sexp_read_char(ctx, in);