2 files changed, 30 insertions, 12 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 05c90be59ba..c35bcb40eba 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,11 @@
+2005-10-23  Lars Hansen <larsh@soem.dk>
+        * emacs-lisp/bytecomp.el (byte-compile-lambda): Add parameter
+        add-lambda.
+        (byte-compile-file-form-defmumble, byte-compile-defun)
+        (byte-compile-defmacro): Use it.
+        (byte-compile-form): Don't call byte-compile-set-symbol-position
+        when a byte-compile handler is called.
+
 2005-10-22  Romain Francoise  <romain@orebokech.com>
 
         * savehist.el (savehist-history-variables): Add `grep-find-history'.
diff --git a/lisp/emacs-lisp/bytecomp.el b/lisp/emacs-lisp/bytecomp.el
index 559d2bd86c6..47bcbbcae6c 100644
--- a/lisp/emacs-lisp/bytecomp.el
+++ b/lisp/emacs-lisp/bytecomp.el
@@ -908,6 +908,13 @@ Each function's symbol gets added to `byte-compile-noruntime-functions'."
 ;; list.  If our current position is after the symbol's position, we
 ;; assume we've already passed that point, and look for the next
 ;; occurrence of the symbol.
+;;
+;; This function should not be called twice for the same occurrence of
+;; a symbol, and it should not be called for symbols generated by the
+;; byte compiler itself; because rather than just fail looking up the
+;; symbol, we may find an occurrence of the symbol further ahead, and
+;; then `byte-compile-last-position' as advanced too far.
+;;
 ;; So your're probably asking yourself: Isn't this function a
 ;; gross hack?  And the answer, of course, would be yes.
 (defun byte-compile-set-symbol-position (sym &optional allow-previous)
@@ -2304,7 +2311,7 @@ list that represents a doc string reference.
                                  ',name ',declaration))
                    outbuffer)))))
 
-    (let* ((new-one (byte-compile-lambda (cons 'lambda (nthcdr 2 form))))
+    (let* ((new-one (byte-compile-lambda (nthcdr 2 form) t))
            (code (byte-compile-byte-code-maker new-one)))
       (if this-one
           (setcdr this-one new-one)
@@ -2500,10 +2507,16 @@ If FORM is a lambda or a macro, byte-compile it as a function."
 ;; Byte-compile a lambda-expression and return a valid function.
 ;; The value is usually a compiled function but may be the original
 ;; lambda-expression.
-(defun byte-compile-lambda (fun)
-  (unless (eq 'lambda (car-safe fun))
-    (error "Not a lambda list: %S" fun))
-  (byte-compile-set-symbol-position 'lambda)
+;; When ADD-LAMBDA is non-nil, the symbol `lambda' is added as head
+;; of the list FUN and `byte-compile-set-symbol-position' is not called.
+;; Use this feature to avoid calling `byte-compile-set-symbol-position'
+;; for symbols generated by the byte compiler itself.
+(defun byte-compile-lambda (fun &optional add-lambda)
+  (if add-lambda
+      (setq fun (cons 'lambda fun))
+    (unless (eq 'lambda (car-safe fun))
+      (error "Not a lambda list: %S" fun))
+    (byte-compile-set-symbol-position 'lambda))
   (byte-compile-check-lambda-list (nth 1 fun))
   (let* ((arglist (nth 1 fun))
          (byte-compile-bound-variables
@@ -2755,9 +2768,7 @@ That command is designed for interactive use only" fn))
                     (or (not (byte-compile-version-cond
                               byte-compile-compatibility))
                         (not (get (get fn 'byte-opcode) 'emacs19-opcode))))
-               (progn
-                 (byte-compile-set-symbol-position fn)
-                 (funcall handler form))
+               (funcall handler form)
              (when (memq 'callargs byte-compile-warnings)
                (if (memq fn '(custom-declare-group custom-declare-variable custom-declare-face))
                    (byte-compile-nogroup-warn form))
@@ -3671,7 +3682,7 @@ that suppresses all warnings during execution of BODY."
          (list 'fset
                (list 'quote (nth 1 form))
                (byte-compile-byte-code-maker
-                (byte-compile-lambda (cons 'lambda (cdr (cdr form)))))))
+                (byte-compile-lambda (cdr (cdr form)) t))))
         (byte-compile-discard))
     ;; We prefer to generate a defalias form so it will record the function
     ;; definition just like interpreting a defun.
@@ -3679,7 +3690,7 @@ that suppresses all warnings during execution of BODY."
      (list 'defalias
            (list 'quote (nth 1 form))
            (byte-compile-byte-code-maker
-            (byte-compile-lambda (cons 'lambda (cdr (cdr form))))))
+            (byte-compile-lambda (cdr (cdr form)) t)))
      t))
   (byte-compile-constant (nth 1 form)))
 
@@ -3688,8 +3699,7 @@ that suppresses all warnings during execution of BODY."
   (byte-compile-body-do-effect
    (list (list 'fset (list 'quote (nth 1 form))
                (let ((code (byte-compile-byte-code-maker
-                            (byte-compile-lambda
-                             (cons 'lambda (cdr (cdr form)))))))
+                            (byte-compile-lambda (cdr (cdr form)) t))))
                  (if (eq (car-safe code) 'make-byte-code)
                      (list 'cons ''macro code)
                    (list 'quote (cons 'macro (eval code))))))