(back_comment): Detect cases where a comment-starter is

actually inside another comment as in:   /* a // b */ c // d \n.
Make it clear that `comstart_pos' is unused for nested comments.

diff --git a/src/ChangeLog b/src/ChangeLog
index 6b847d3f35d70bbaf16958cee15236556b2517ed..b9fcac51fc4956f36d2c6089ca5d043e4d0ae80c 100644 (file)
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,21 @@
+2000-08-27  Stefan Monnier  <monnier@cs.yale.edu>
+
+       * syntax.c (back_comment): Detect cases where a comment-starter is
+       actually inside another comment as in:   /* a // b */ c // d \n.
+       Make it clear that `comstart_pos' is unused for nested comments.
+
+       * keymap.c (store_in_keymap, fix_submap_inheritance): New prototypes.
+       (KEYMAPP): New macro.
+       (Fkeymap_parent, Fset_keymap_parent): Use it.
+       (fix_submap_inheritance): Mark it static.
+       (define_as_prefix, describe_buffer_bindings, describe_command)
+       (describe_translation, describe_map): Complete prototypes.
+
+       * lisp.h (store_in_keymap, fix_submap_inheritance): Remove.
+
+       * keyboard.c (menu_bar_item): Detect duplicate entries for all items
+       to better match the key-lookup behavior.
+
 2000-08-27  Gerd Moellmann  <gerd@gnu.org>
 
        * xfaces.c (lface_fully_specified_p): Handle :inherit.

diff --git a/src/syntax.c b/src/syntax.c
index 9e5247064ef6e01db6e9f31cda867495244c7a07..189e50d096324b39c65b2af997f0981b3ea03f42 100644 (file)
--- a/src/syntax.c
+++ b/src/syntax.c
@@ -469,12 +469,16 @@ back_comment (from, from_byte, stop, comnested, comstyle, charpos_ptr, bytepos_p
      PARITY is current parity of quotes from the comment end.  */
   int string_style = -1;       /* Presumed outside of any string. */
   int string_lossage = 0;
+  /* Not a real lossage: indicates that we have passed a matching comment
+     starter plus an non-matching comment-ender, meaning that any matching
+     comment-starter we might see later could be a false positive (hidden
+     inside another comment).
+     Test case:  { a (* b } c (* d *) */
+  int comment_lossage = 0;
   int comment_end = from;
   int comment_end_byte = from_byte;
   int comstart_pos = 0;
   int comstart_byte;
-  /* Value that PARITY had, when we reached the position
-     in COMSTART_POS.  */
   int scanstart = from - 1;
   /* Place where the containing defun starts,
      or 0 if we didn't come across it yet.  */
@@ -548,23 +552,24 @@ back_comment (from, from_byte, stop, comnested, comstyle, charpos_ptr, bytepos_p
          
        case Scomment:
          /* We've already checked that it is the relevant comstyle.  */
-         if (string_style != -1 || string_lossage)
+         if (string_style != -1 || comment_lossage || string_lossage)
            /* There are odd string quotes involved, so let's be careful.
               Test case in Pascal: " { " a { " } */
            goto lossage;
 
-         if (comnested && --nesting <= 0)
+         if (!comnested)
+           {
+             /* Record best comment-starter so far.  */
+             comstart_pos = from;
+             comstart_byte = from_byte;
+           }
+         else if (--nesting <= 0)
            /* nested comments have to be balanced, so we don't need to
               keep looking for earlier ones.  We use here the same (slightly
               incorrect) reasoning as below:  since it is followed by uniform
               paired string quotes, this comment-start has to be outside of
               strings, else the comment-end itself would be inside a string. */
            goto done;
-
-         /* Record comment-starters according to that
-            quote-parity to the comment-end.  */
-         comstart_pos = from;
-         comstart_byte = from_byte;
          break;
 
        case Sendcomment:
@@ -578,6 +583,15 @@ back_comment (from, from_byte, stop, comnested, comstyle, charpos_ptr, bytepos_p
                   this comment-ender rather than ours.  */
                from = stop;    /* Break out of the loop.  */
            }
+         else if (comstart_pos != 0 || c != '\n')
+           /* We're mixing comment styles here, so we'd better be careful.
+              The (comstart_pos != 0 || c != '\n') check is not quite correct
+              (we should just always set comment_lossage), but removing it
+              would imply that any multiline comment in C would go through
+              lossage, which seems overkill.
+              The failure should only happen in the rare cases such as
+                { (* } *)   */
+           comment_lossage = 1;
          break;
 
        case Sopen:
@@ -594,7 +608,7 @@ back_comment (from, from_byte, stop, comnested, comstyle, charpos_ptr, bytepos_p
          break;
 
        default:
-         continue;
+         break;
        }
     }
 
@@ -604,12 +618,9 @@ back_comment (from, from_byte, stop, comnested, comstyle, charpos_ptr, bytepos_p
       from_byte = comment_end_byte;
       UPDATE_SYNTAX_TABLE_FORWARD (comment_end - 1);
     }
-  /* If the earliest comment starter
-     is followed by uniform paired string quotes or none,
-     we know it can't be inside a string
-     since if it were then the comment ender would be inside one.
-     So it does start a comment.  Skip back to it.  */
-  else if (!comnested)
+  /* If comstart_pos is set and we get here (ie. didn't jump to `lossage'
+     or `done'), then we've found the beginning of the non-nested comment.  */
+  else if (1)  /* !comnested */
     {
       from = comstart_pos;
       from_byte = comstart_byte;