cider-docstring--format: nil-safe (#3722)

* call cider-docstring--format after checking argument

* use when-let for DRY

* add CHANGELOG entry

CHANGELOG.md

@@ -17,6 +17,7 @@
 - [#3719](https://github.com/clojure-emacs/cider/pull/3719): Remove duplicated keybinding.
 - Bump the injected `cider-nrepl` to [0.49.1](https://github.com/clojure-emacs/cider-nrepl/blob/master/CHANGELOG.md#0491-2024-06-30).
   - Reduces the minimal supported Clojure version to 1.10.0 (from 1.10.3).
+- [#3722](https://github.com/clojure-emacs/cider/pull/3722): Call `cider-docstring--format` after checking argument
 
 ### Bugs fixed
 

cider-eldoc.el

@@ -218,9 +218,9 @@ information."
          (symbol (lax-plist-get eldoc-info "symbol"))
          (docstring (or (cider--render-docstring-first-sentence eldoc-info)
                         (cider--render-docstring eldoc-info)
-                        (cider-docstring--trim
-                         (cider-docstring--format
-                          (lax-plist-get eldoc-info "docstring")))))
+                        (when-let (docstring (lax-plist-get eldoc-info "docstring"))
+                          (cider-docstring--trim
+                           (cider-docstring--format docstring)))))
          ;; if it's a single class (and not multiple class candidates), that's it
          (maybe-class (car (lax-plist-get eldoc-info "class")))
          (formatted-var (or (when maybe-class