[Fix #2058] Don't cache non-existing ns-forms

Author: vspinu

CHANGELOG.md

@@ -8,6 +8,7 @@
 
 ### Bugs Fixed
 
+* [#2058](https://github.com/clojure-emacs/cider/pull/2058) Don't cache ns-forms in buffers with no such forms.
 * [#2057](https://github.com/clojure-emacs/cider/pull/2057) Use `cider--font-lock-ensure` for compatibility with Emacs 24.5.
 
 ## 0.15.0 (2017-07-20)

cider-interaction.el

@@ -1604,7 +1604,8 @@ ClojureScript REPL exists for the project, it is evaluated in both REPLs."
           (ns-form  (cider-ns-form)))
       (cider-map-connections
        (lambda (connection)
-         (cider-repl--cache-ns-form ns-form connection)
+         (when ns-form
+           (cider-repl--cache-ns-form ns-form connection))
          (cider-request:load-file (cider-file-string filename)
                                   (funcall cider-to-nrepl-filename-function
                                            (cider--server-filename filename))

test/cider-client-tests.el

@@ -111,6 +111,20 @@ SYMBOL is locally let-bound to the current buffer."
                 (setq major-mode 'clojurescript-mode)
                 (expect (cider-current-connection) :to-equal bb2)))))))
 
+    (describe "when current buffer is a 'multi' buffer"
+      (describe "when there is only one connection available"
+       (it "returns the only connection"
+         (with-connection-buffer "clj" b
+           (with-temp-buffer
+             (clojure-mode)
+             (expect (cider-current-connection "clj") :to-equal b))
+           (with-temp-buffer
+             (clojurec-mode)
+             (expect (cider-current-connection "clj") :to-equal b))
+           (with-temp-buffer
+             (clojurex-mode)
+             (expect (cider-current-connection "clj") :to-equal b))))))
+
     (describe "when type argument is given"
       (describe "when connection of that type exists"
         (it "returns that connection buffer"