Fix bugs in `auth-source-netrc-parse-one'.

* lisp/auth-source.el (auth-source-netrc-parse-one): Ensure that match
  data is not overwritten in `auth-source-netrc-parse-next-interesting'.
  Ensure that blanks are skipped before and after going over comments
  and eols.
* test/lisp/auth-source-tests.el (auth-source-test-netrc-parse-one): New test.

(cherry picked from commit 60ff8101449eea3a5ca4961299501efd83d011bd)

1 files changed, 7 insertions, 5 deletions

diff --git a/lisp/auth-source.el b/lisp/auth-source.el
index 374b7f1e86c..afb35c8f044 100644
--- a/lisp/auth-source.el
+++ b/lisp/auth-source.el
@@ -984,12 +984,13 @@ Note that the MAX parameter is used so we can exit the parse early."
 
 (defun auth-source-netrc-parse-next-interesting ()
   "Advance to the next interesting position in the current buffer."
+  (skip-chars-forward "\t ")
   ;; If we're looking at a comment or are at the end of the line, move forward
-  (while (or (looking-at "#")
+  (while (or (eq (char-after) ?#)
              (and (eolp)
                   (not (eobp))))
-    (forward-line 1))
-  (skip-chars-forward "\t "))
+    (forward-line 1)
+    (skip-chars-forward "\t ")))
 
 (defun auth-source-netrc-parse-one ()
   "Read one thing from the current buffer."
@@ -999,8 +1000,9 @@ Note that the MAX parameter is used so we can exit the parse early."
             (looking-at "\"\\([^\"]*\\)\"")
             (looking-at "\\([^ \t\n]+\\)"))
     (forward-char (length (match-string 0)))
-    (auth-source-netrc-parse-next-interesting)
-    (match-string-no-properties 1)))
+    (prog1
+        (match-string-no-properties 1)
+      (auth-source-netrc-parse-next-interesting))))
 
 ;; with thanks to org-mode
 (defsubst auth-source-current-line (&optional pos)