Improve ffap-gopher-at-point handling of long lines

* lisp/ffap.el (ffap-gopher-regexp): Only match the KEY part.  Note
setting to nil is now supported.
(ffap--gopher-var-on-line): New function.
(ffap-gopher-at-point): Use it instead of the old ffap-gopher-regexp
which could overflow the regexp stack on long lines (Bug#25391).  Use
`let-alist' instead of calling `set' on local variables.
* test/lisp/ffap-tests.el (ffap-gopher-at-point): New test.

1 files changed, 17 insertions, 0 deletions

diff --git a/test/lisp/ffap-tests.el b/test/lisp/ffap-tests.el
index 1ba5f86a887..a3fe3502461 100644
--- a/test/lisp/ffap-tests.el
+++ b/test/lisp/ffap-tests.el
@@ -49,6 +49,23 @@ index 3d7cebadcf..ad4b70d737 100644
               (should (equal '(1 1) ffap-string-at-point-region)))))
       (and (file-exists-p file) (delete-file file)))))
 
+(ert-deftest ffap-gopher-at-point ()
+  (with-temp-buffer
+    (insert "\
+Type = 1
+Name = foo
+Path = /the/path
+Port = 7070
+Host = example.com\n")
+    (should-not (ffap-gopher-at-point))
+    (goto-char (point-min))
+    (should (equal (ffap-gopher-at-point)
+                   "gopher://example.com:7070/1/the/path"))
+    (should (equal ffap-string-at-point-region
+                   (list (point-min) (point-max))))
+    (let ((ffap-gopher-regexp nil))
+      (should-not (ffap-gopher-at-point)))))
+
 (provide 'ffap-tests)
 
 ;;; ffap-tests.el ends here