BUG: Fix cmake-mode.el indentation cursor motion

This makes cursor motion in the indent function consistent with emacs
conventions.  Patch from Mike Wittman.  See issue #8625.

Docs/cmake-mode.el

@@ -102,15 +102,18 @@
 (defun cmake-indent ()
   "Indent current line as CMAKE code."
   (interactive)
-  (beginning-of-line)
   (if (cmake-line-starts-inside-string)
       ()
     (if (bobp)
-        (indent-line-to 0)
-      (let ((point-start (point))
-            token cur-indent)
+        (cmake-indent-line-to 0)
+      (let (cur-indent)
 
         (save-excursion
+          (beginning-of-line)
+
+          (let ((point-start (point))
+                token)
+
             ; Search back for the last indented line.
             (cmake-find-last-indented-line)
 
@@ -133,23 +136,36 @@
                   (setq cur-indent (+ cur-indent cmake-tab-width))
                 )
               )
-          )
+            (goto-char point-start)
 
             ; If this is the end of a block, decrease indentation.
             (if (looking-at cmake-regex-block-close)
                 (setq cur-indent (- cur-indent cmake-tab-width))
               )
+            )
+          )
 
         ; Indent this line by the amount selected.
         (if (< cur-indent 0)
-            (indent-line-to 0)
-          (indent-line-to cur-indent)
+            (cmake-indent-line-to 0)
+          (cmake-indent-line-to cur-indent)
           )
         )
       )
     )
   )
 
+(defun cmake-point-in-indendation ()
+  (string-match "^[ \\t]*$" (buffer-substring (point-at-bol) (point))))
+
+(defun cmake-indent-line-to (column)
+  "Indent the current line to COLUMN.
+If point is within the existing indentation it is moved to the end of
+the indentation.  Otherwise it retains the same position on the line"
+  (if (cmake-point-in-indendation)
+      (indent-line-to column)
+    (save-excursion (indent-line-to column))))
+
 ;------------------------------------------------------------------------------
 
 ;;