(describe_syntax): Recognize the `n'estable bit.

(Fforward_comment, scan_lists):
Check the comstyle of single-char comment-starters.
(scan_sexps_forward): Don't try to recognize `half comment-enders' if
we're just at the beginning of the comment (f.ex with (*) ... (*)).

2 files changed, 23 insertions, 5 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index e2390acf373..d2fb087ce16 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,11 @@
+2000-06-20  Stefan Monnier  <monnier@cs.yale.edu>
+
+        * syntax.c (describe_syntax): Recognize the `n'estable bit.
+        (Fforward_comment, scan_lists):
+        Check the comstyle of single-char comment-starters.
+        (scan_sexps_forward): Don't try to recognize `half comment-enders' if
+        we're just at the beginning of the comment (f.ex with (*) ... (*)).
+
 2000-06-20  Dave Love  <fx@gnu.org>
 
         * fns.c (make_hash_table, maybe_resize_hash_table): Cast arg of
diff --git a/src/syntax.c b/src/syntax.c
index 19e18127f0b..eedec27d549 100644
--- a/src/syntax.c
+++ b/src/syntax.c
@@ -970,7 +970,7 @@ describe_syntax (value)
     Lisp_Object value;
 {
   register enum syntaxcode code;
-  char desc, start1, start2, end1, end2, prefix, comstyle;
+  char desc, start1, start2, end1, end2, prefix, comstyle, comnested;
   char str[2];
   Lisp_Object first, match_lisp;
 
@@ -1010,6 +1010,7 @@ describe_syntax (value)
   end2 = (XINT (first) >> 19) & 1;
   prefix = (XINT (first) >> 20) & 1;
   comstyle = (XINT (first) >> 21) & 1;
+  comnested = (XINT (first) >> 22) & 1;
 
   if ((int) code < 0 || (int) code >= (int) Smax)
     {
@@ -1040,6 +1041,8 @@ describe_syntax (value)
     insert ("p", 1);
   if (comstyle)
     insert ("b", 1);
+  if (comnested)
+    insert ("n", 1);
 
   insert_string ("\twhich means: ");
 
@@ -1093,6 +1096,8 @@ describe_syntax (value)
     insert_string (",\n\t  is the second character of a comment-end sequence");
   if (comstyle)
     insert_string (" (comment style b)");
+  if (comnested)
+    insert_string (" (nestable)");
 
   if (prefix)
     insert_string (",\n\t  is a prefix character for `backward-prefix-chars'");
@@ -1777,9 +1782,9 @@ between them, return t; otherwise return nil.")
           code = SYNTAX (c);
           comstart_first = SYNTAX_COMSTART_FIRST (c);
           comnested = SYNTAX_COMMENT_NESTED (c);
+          comstyle = SYNTAX_COMMENT_STYLE (c);
           INC_BOTH (from, from_byte);
           UPDATE_SYNTAX_TABLE_FORWARD (from);
-          comstyle = 0;
           if (from < stop && comstart_first
               && (c1 = FETCH_CHAR (from_byte),
                   SYNTAX_COMSTART_SECOND (c1)))
@@ -1991,6 +1996,7 @@ scan_lists (from, count, depth, sexpflag)
           code = SYNTAX_WITH_MULTIBYTE_CHECK (c);
           comstart_first = SYNTAX_COMSTART_FIRST (c);
           comnested = SYNTAX_COMMENT_NESTED (c);
+          comstyle = SYNTAX_COMMENT_STYLE (c);
           prefix = SYNTAX_PREFIX (c);
           if (depth == min_depth)
             last_good = from;
@@ -2171,7 +2177,7 @@ scan_lists (from, count, depth, sexpflag)
             }
           
           /* Quoting turns anything except a comment-ender
-             into a word character.  Note that this if cannot be true
+             into a word character.  Note that this cannot be true
              if we decremented FROM in the if-statement above.  */
           if (code != Sendcomment && char_quoted (from, from_byte))
             code = Sword;
@@ -2648,10 +2654,14 @@ do { prev_from = from;				\
         commentloop:
           /* The (from == BEGV) test is to enter the loop in the middle so
              that we find a 2-char comment ender even if we start in the
-             middle of it.  */
+             middle of it.  We don't want to do that if we're just at the
+             beginning of the comment (think of (*) ... (*)).
+             Actually, the current code still doesn't handle such cases right
+             when the comment style allows nesting.  */
           found = forw_comment (from, from_byte, end,
                                 state.incomment, state.comstyle,
-                                (from == BEGV) ? 0 : prev_from_syntax,
+                                (from == BEGV || from < state.comstr_start + 3)
+                                ? 0 : prev_from_syntax,
                                 &out_charpos, &out_bytepos, &state.incomment);
           from = out_charpos; from_byte = out_bytepos;
           /* Beware!  prev_from and friends are invalid now.