Preserve line numbers for blank lines.

This allows differentiating between indenting a blank line and re-indenting the
line before it.  This situation occurs fairly often: it happens every time the
user hits re turn to create a new line, which calls indentation function on the
previous line and the newly created line separately.  Before this fix, these two
calls would incorrectly calculate the same indentation level, e.g. when the
previous line just created a block.

Author: maemre

scala-mode-indent.el

@@ -746,10 +746,17 @@ tokenization. The parser is not anything like well-formalized, but it can start
 at an arbitrary point in the buffer, and except in pathological cases, look at
 relatively few lines in order to make a good guess; and it is tolerant to a
 certain amount of incorrect or in-progress syntactic forms."
-  (let* ((initResult (scala-indent:find-analysis-start point))
+  (let* ((line-no
+          ;; Get the line number while taking blanks into account.  This allows
+          ;; differentiating between indenting at a blank line and re-indenting
+          ;; at the line right before it.
+          (line-number-at-pos
+           (save-excursion
+             (when point (goto-char point))
+             (point))))
+         (initResult (scala-indent:find-analysis-start point))
          (point (car initResult))
          (stack (cadr initResult))
-         (line-no (line-number-at-pos point))
          (analysis (scala-indent:analyze-context point stack))
          (syntax-elem (list (nth 0 analysis)))
          (ctxt-line (nth 1 analysis))