Fix failing tests, and add a test for the fix.

Author: bmastenbrook

rust-mode-tests.el

@@ -164,6 +164,15 @@ Also, the result should be the same regardless of whether the code is at the beg
      //
      // This is the second really really really really really really long paragraph" 1 89))
 
+(ert-deftest fill-paragraph-multi-line-style-comment ()
+  (test-fill-paragraph
+   "/* This is a very very very very very very very very long string
+ */"
+   "/* This is a very very very very
+ * very very very very long
+ * string
+ */"))
+
 (ert-deftest fill-paragraph-multi-line-style-inner-doc-comment ()
   (test-fill-paragraph
    "/*! This is a very very very very very very very long string

rust-mode.el

@@ -1058,10 +1058,13 @@ the desired identifiers), but does not match type annotations \"foo::<\"."
   (let ((result
          ;; Replace /* with same number of spaces
          (replace-regexp-in-string
-          "\\(?:/\\*+\\)"
+          "\\(?:/\\*+\\)[!*]?"
           (lambda (s)
             ;; We want the * to line up with the first * of the comment start
-            (concat (make-string (- (length s) 1) ?\x20) "*"))
+            (concat (make-string (- (length s)
+                                    (if (or (string-suffix-p "!" s)
+                                            (string-suffix-p "**" s)) 2 1))
+                                 ?\x20) "*"))
           line-start)))
     ;; Make sure we've got at least one space at the end
     (if (not (= (aref result (- (length result) 1)) ?\x20))