Open partial links in Emacs, full URLs in browser

This commit changes the behavior of `markdown-follow-link-at-point` (C-c
C-o).  If the link is a complete URL, open in browser with `browse-url'.
Otherwise, open with `find-file' after stripping anchor and/or query
string.  Includes a test.

markdown-mode.el

@@ -942,6 +942,7 @@
 (require 'outline)
 (require 'thingatpt)
 (require 'cl-lib)
+(require 'url-parse)
 
 (defvar jit-lock-start)
 (defvar jit-lock-end)
@@ -6191,9 +6192,18 @@ not at a link or the link reference is not defined returns nil."
    (t nil)))
 
 (defun markdown-follow-link-at-point ()
-  "Open the current non-wiki link in a browser."
+  "Open the current non-wiki link.
+If the link is a complete URL, open in browser with `browse-url'.
+Otherwise, open with `find-file' after stripping anchor and/or query string."
   (interactive)
-  (if (markdown-link-p) (browse-url (markdown-link-link))
+  (if (markdown-link-p)
+      (let* ((link (markdown-link-link))
+             (struct (url-generic-parse-url link)))
+        (if (url-fullness struct)
+            ;; Open full URLs in browser
+            (browse-url link)
+          ;; Strip query string and open partial URLs in Emacs
+          (find-file (car (url-path-and-query struct)))))
     (error "Point is not at a Markdown link or URI")))
 
 

tests/markdown-test.el

@@ -3349,9 +3349,24 @@ like statement. Detail: https://github.com/jrblevin/markdown-mode/issues/75"
       (call-interactively #'markdown-backward-same-level)
       (should (looking-at-p "## Header 2-1")))))
 
+;;; Link tests:
+
+(ert-deftest test-markdown-link/follow ()
+  "Test link following in a browser and in Emacs."
+  (markdown-test-string "[text](http://path?query=foo#id)"
+    (let* ((opened-url nil)
+           (browse-url-browser-function
+            (lambda (url &rest args) (setq opened-url url))))
+      (markdown-follow-thing-at-point nil)
+      (should (equal opened-url "http://path?query=foo#id"))))
+  (markdown-test-string "[text](path?query=foo#id)"
+    (markdown-follow-thing-at-point nil)
+    (should (equal (file-name-nondirectory (buffer-file-name)) "path"))
+    (kill-buffer)))
+
 ;;; Wiki link tests:
 
-(ert-deftest test-markdown-wiki-link/file-local-variabls ()
+(ert-deftest test-markdown-wiki-link/file-local-variables ()
   "Test enabling wiki links via file-local variables."
   (markdown-test-file "wiki-links.text"
    (should-not markdown-enable-wiki-links)