Don't error if the first line of the file is empty.

We can't go back before (point-min), and Emacs errors if we try.

contrib/julia-mode.el

@@ -234,6 +234,7 @@ Handles both single-line and multi-line comments."
  (cond
  ((julia-in-comment) nil)
  ((julia-in-string) nil)
+ ((<= (point) (1+ (point-min))) nil)
  (:else
  (save-excursion
  ;; See if point is inside a character, e.g. '|x'
@@ -242,17 +243,18 @@ Handles both single-line and multi-line comments."
  (backward-char 1)
  ;; Move back one more character, as julia-char-regex checks
  ;; for whitespace/paren/etc before the single quote.
- (backward-char 1)
+ (ignore-errors (backward-char 1)) ; ignore error from being at (point-min)
 
  (if (looking-at julia-char-regex)
  t
  ;; If point was in a \ character (i.e. we started at '\|\'),
  ;; we need to move back once more.
- (if (looking-at (rx "'\\"))
- (progn
- (backward-char 1)
- (looking-at julia-char-regex))
- nil))))))
+ (ignore-errors
+ (if (looking-at (rx "'\\"))
+ (progn
+ (backward-char 1)
+ (looking-at julia-char-regex))
+ nil)))))))
 
 (defun julia-in-brackets ()
  "Return non-nil if point is inside square brackets."
@@ -322,6 +324,12 @@ Do not move back beyond MIN."
  (goto-char pos)
  (+ julia-basic-offset (current-indentation))))))
 
+(defsubst julia--safe-backward-char ()
+ "Move back one character, but don't error if we're at the
+beginning of the buffer."
+ (unless (eq (point) (point-min))
+ (backward-char)))
+
 (defun julia-paren-indent ()
  "Return the column position of the innermost containing paren
 before point. Returns nil if we're not within nested parens."
@@ -339,7 +347,7 @@ before point. Returns nil if we're not within nested parens."
  ((looking-at (rx (any "]" ")")))
  (decf open-count)))))
 
- (backward-char))
+ (julia--safe-backward-char))
 
  (if (plusp open-count)
  (+ (current-column) 2)
@@ -364,14 +372,15 @@ before point. Returns nil if we're not within nested parens."
  (ignore-errors (+ (julia-last-open-block (point-min))
  (if endtok (- julia-basic-offset) 0)))))
  ;; If the previous line ends in =, increase the indent.
- (save-excursion
- (if (and (not (equal (point-min) (line-beginning-position)))
- (progn
- (forward-line -1)
- (end-of-line) (backward-char 1)
- (equal (char-after (point)) ?=)))
- (+ julia-basic-offset (current-indentation))
- nil))
+ (ignore-errors ; if previous line is (point-min)
+ (save-excursion
+ (if (and (not (equal (point-min) (line-beginning-position)))
+ (progn
+ (forward-line -1)
+ (end-of-line) (backward-char 1)
+ (equal (char-after (point)) ?=)))
+ (+ julia-basic-offset (current-indentation))
+ nil)))
  ;; Otherwise, use the same indentation as previous line.
  (save-excursion (forward-line -1)
  (current-indentation))