Merge from origin/emacs-26

868eb74f91 Simplify make-progress-reporter vs float-time
83db9a1bba Fix two more minor Gnus typos
e655946ce0 Fix two minor Gnus typos
6a00914d6d Tweak Fdocumentation's error for an undefined function
7c63655e39 Tweak format of list of old files in NEWS header

# Conflicts:
#	etc/NEWS

1 files changed, 2 insertions, 0 deletions

diff --git a/src/doc.c b/src/doc.c
index 3286c12675a..e81740bfc1c 100644
--- a/src/doc.c
+++ b/src/doc.c
@@ -336,6 +336,8 @@ string is passed through `substitute-command-keys'.  */)
     }
 
   fun = Findirect_function (function, Qnil);
+  if (NILP (fun))
+    xsignal1 (Qvoid_function, function);
   if (CONSP (fun) && EQ (XCAR (fun), Qmacro))
     fun = XCDR (fun);
   if (SUBRP (fun))