Protect against empty uris on windows

Per https://github.com/joaotavora/eglot/issues/630.

* eglot.el (eglot--uri-to-path): Check string length

Co-authored-by: João Távora <joaotavora@gmail.com>
GitHub-reference: fix https://github.com/joaotavora/eglot/issues/610

diff --git a/lisp/progmodes/eglot.el b/lisp/progmodes/eglot.el
index 017b8200bfadd89cb0348c2ecf078d8fcb1cb3aa..0cb5839f6d5d6b413f10741ea4deaf73824b95aa 100644 (file)
--- a/lisp/progmodes/eglot.el
+++ b/lisp/progmodes/eglot.el
@@ -1176,7 +1176,8 @@ If optional MARKER, return a marker instead"
   "Convert URI to a file path."
   (when (keywordp uri) (setq uri (substring (symbol-name uri) 1)))
   (let ((retval (url-filename (url-generic-parse-url (url-unhex-string uri)))))
-    (if (eq system-type 'windows-nt) (substring retval 1) retval)))
+    (if (and (eq system-type 'windows-nt) (cl-plusp (length retval)))
+        (substring retval 1) retval)))
 
 (defun eglot--snippet-expansion-fn ()
   "Compute a function to expand snippets.