(record_overlay_string, overlay_strings): Handle zero-sized overlays better.

diff --git a/src/buffer.c b/src/buffer.c
index 129fee7c095c275650d99de4637a9868259d6ff5..ee7dce84a5b056bb0d24a699f61107b8acc21e42 100644 (file)
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -1949,7 +1949,7 @@ sort_overlays (overlay_vec, noverlays, w)
 \f
 struct sortstr
 {
-  Lisp_Object string;
+  Lisp_Object string, string2;
   int size;
   int priority;
 };
@@ -1987,10 +1987,9 @@ cmp_for_strings (as1, as2)
 }
 
 static void
-record_overlay_string (ssl, str, pri, size)
+record_overlay_string (ssl, str, str2, pri, size)
      struct sortstrlist *ssl;
-     Lisp_Object str;
-     Lisp_Object pri;
+     Lisp_Object str, str2, pri;
      int size;
 {
   if (ssl->used == ssl->size)
@@ -2003,19 +2002,26 @@ record_overlay_string (ssl, str, pri, size)
                  xrealloc (ssl->buf, ssl->size * sizeof (struct sortstr)));
     }
   ssl->buf[ssl->used].string = str;
+  ssl->buf[ssl->used].string2 = str2;
   ssl->buf[ssl->used].size = size;
   ssl->buf[ssl->used].priority = (INTEGERP (pri) ? XINT (pri) : 0);
   ssl->used++;
   ssl->bytes += XSTRING (str)->size;
+  if (STRINGP (str2))
+    ssl->bytes += XSTRING (str2)->size;
 }
 
 /* Return the concatenation of the strings associated with overlays that
    begin or end at POS, ignoring overlays that are specific to a window
    other than W.  The strings are concatenated in the appropriate order:
    shorter overlays nest inside longer ones, and higher priority inside
-   lower.  Returns the string length, and stores the contents indirectly
-   through PSTR, if that variable is non-null.  The string may be
-   overwritten by subsequent calls.  */
+   lower.  Normally all of the after-strings come first, but zero-sized
+   overlays have their after-strings ride along with the before-strings
+   because it would look strange to print them inside-out.
+
+   Returns the string length, and stores the contents indirectly through
+   PSTR, if that variable is non-null.  The string may be overwritten by
+   subsequent calls.  */
 int
 overlay_strings (pos, w, pstr)
      int pos;
@@ -2042,14 +2048,17 @@ overlay_strings (pos, w, pstr)
       window = Foverlay_get (overlay, Qwindow);
       if (WINDOWP (window) && XWINDOW (window) != w)
        continue;
-      if (endpos == pos
-         && (str = Foverlay_get (overlay, Qafter_string), STRINGP (str)))
-       record_overlay_string (&overlay_tails, str,
-                              Foverlay_get (overlay, Qpriority),
-                              endpos - startpos);
       if (startpos == pos
          && (str = Foverlay_get (overlay, Qbefore_string), STRINGP (str)))
        record_overlay_string (&overlay_heads, str,
+                              (startpos == endpos
+                               ? Foverlay_get (overlay, Qafter_string)
+                               : Qnil),
+                              Foverlay_get (overlay, Qpriority),
+                              endpos - startpos);
+      else if (endpos == pos
+         && (str = Foverlay_get (overlay, Qafter_string), STRINGP (str)))
+       record_overlay_string (&overlay_tails, str, Qnil,
                               Foverlay_get (overlay, Qpriority),
                               endpos - startpos);
     }
@@ -2068,14 +2077,17 @@ overlay_strings (pos, w, pstr)
       window = Foverlay_get (overlay, Qwindow);
       if (WINDOWP (window) && XWINDOW (window) != w)
        continue;
-      if (endpos == pos
-         && (str = Foverlay_get (overlay, Qafter_string), STRINGP (str)))
-       record_overlay_string (&overlay_tails, str,
-                              Foverlay_get (overlay, Qpriority),
-                              endpos - startpos);
       if (startpos == pos
          && (str = Foverlay_get (overlay, Qbefore_string), STRINGP (str)))
        record_overlay_string (&overlay_heads, str,
+                              (startpos == endpos
+                               ? Foverlay_get (overlay, Qafter_string)
+                               : Qnil),
+                              Foverlay_get (overlay, Qpriority),
+                              endpos - startpos);
+      else if (endpos == pos
+              && (str = Foverlay_get (overlay, Qafter_string), STRINGP (str)))
+       record_overlay_string (&overlay_tails, str, Qnil,
                               Foverlay_get (overlay, Qpriority),
                               endpos - startpos);
     }
@@ -2107,7 +2119,15 @@ overlay_strings (pos, w, pstr)
          tem = overlay_heads.buf[i].string;
          bcopy (XSTRING (tem)->data, p, XSTRING (tem)->size);
          p += XSTRING (tem)->size;
+         tem = overlay_heads.buf[i].string2;
+         if (STRINGP (tem))
+           {
+             bcopy (XSTRING (tem)->data, p, XSTRING (tem)->size);
+             p += XSTRING (tem)->size;
+           }
        }
+      if (p != overlay_str_buf + total)
+       abort ();
       if (pstr)
        *pstr = overlay_str_buf;
       return total;