Improve doc string and prompt of 'grep-read-files'

* lisp/progmodes/grep.el (grep-read-files): Clarify in the doc
string and in the prompt that shell wildcards can be used.
Suggested by Allen Li <vianchielfaura@gmail.com>.  (Bug#28615)

1 files changed, 3 insertions, 2 deletions

diff --git a/lisp/progmodes/grep.el b/lisp/progmodes/grep.el
index 01bdb04714f..d0404fdeaf4 100644
--- a/lisp/progmodes/grep.el
+++ b/lisp/progmodes/grep.el
@@ -903,7 +903,8 @@ substitution string.  Note dynamic scoping of variables.")
   (read-regexp "Search for" 'grep-tag-default 'grep-regexp-history))
 
 (defun grep-read-files (regexp)
-  "Read files arg for interactive grep."
+  "Read a file-name pattern arg for interactive grep.
+The pattern can include shell wildcards."
   (let* ((bn (or (buffer-file-name)
                  (replace-regexp-in-string "<[0-9]+>\\'" "" (buffer-name))))
          (fn (and bn
@@ -936,7 +937,7 @@ substitution string.  Note dynamic scoping of variables.")
                (car (car grep-files-aliases))))
          (files (completing-read
                  (concat "Search for \"" regexp
-                         "\" in files"
+                         "\" in files matching wildcard"
                          (if default (concat " (default " default ")"))
                          ": ")
                  'read-file-name-internal