lisp/*.el, src/*.c: Doc fixes related to returning t vs non-nil

* lisp/progmodes/flymake-proc.el (flymake-proc--find-buffer-for-file):
Doc fix; return value is a buffer, not t.

* lisp/progmodes/ebrowse.el (ebrowse-member-display-p):
Doc fix; return value is the MEMBER argument, not nil.

* lisp/files.el (hack-one-local-variable-eval-safep):
* lisp/play/doctor.el (doctor-nounp, doctor-pronounp):
* lisp/progmodes/flymake-proc.el (flymake-proc--check-include):
* lisp/progmodes/js.el (js--broken-arrow-terminates-line-p):
Doc fix; a non-nil return value is not always t.

* lisp/image.el (image-type-available-p):
* lisp/simple.el (region-active-p):
* lisp/window.el (frame-root-window-p):
* src/buffer.c (Fbuffer_live_p):
* src/image.c (Finit_image_library):
* src/window.c (Fwindow_minibuffer_p):
Doc fix; a non-nil return value is always t.

* doc/lispref/minibuf.texi (Minibuffer Windows): Doc fix.

3 files changed, 5 insertions, 4 deletions

diff --git a/lisp/progmodes/ebrowse.el b/lisp/progmodes/ebrowse.el
index 733e3735821..eb0ec87a222 100644
--- a/lisp/progmodes/ebrowse.el
+++ b/lisp/progmodes/ebrowse.el
@@ -2641,7 +2641,8 @@ means the member buffer is standalone.  CLASS is its class."
 
 
 (defun ebrowse-member-display-p (member)
-  "Return t if MEMBER must be displayed under the current filter settings."
+  "Check if MEMBER must be displayed under the current filter settings.
+If so, return MEMBER; otherwise return nil."
   (if (and (aref ebrowse--filters (ebrowse-ms-visibility member))
            (or (null ebrowse--const-display-flag)
                (ebrowse-const-p member))
diff --git a/lisp/progmodes/flymake-proc.el b/lisp/progmodes/flymake-proc.el
index f08ba2f3681..571ee170e32 100644
--- a/lisp/progmodes/flymake-proc.el
+++ b/lisp/progmodes/flymake-proc.el
@@ -444,7 +444,7 @@ instead of reading master file from disk."
 
 (defun flymake-proc--check-include (source-file-name inc-name include-dirs)
   "Check if SOURCE-FILE-NAME can be found in include path.
-Return t if it can be found via include path using INC-NAME."
+Return non-nil if it can be found via include path using INC-NAME."
   (if (file-name-absolute-p inc-name)
       (flymake-proc--same-files source-file-name inc-name)
     (while (and include-dirs
@@ -458,7 +458,7 @@ Return t if it can be found via include path using INC-NAME."
 
 (defun flymake-proc--find-buffer-for-file (file-name)
   "Check if there exists a buffer visiting FILE-NAME.
-Return t if so, nil if not."
+Return the buffer if it exists, nil if not."
   (let ((buffer-name (get-file-buffer file-name)))
     (if buffer-name
         (get-buffer buffer-name))))
diff --git a/lisp/progmodes/js.el b/lisp/progmodes/js.el
index 8d457a28ec2..599923dd279 100644
--- a/lisp/progmodes/js.el
+++ b/lisp/progmodes/js.el
@@ -2703,7 +2703,7 @@ Whitespace and comments around the arrow are ignored.")
 
 (defun js--broken-arrow-terminates-line-p ()
   "Helper function for `js--proper-indentation'.
-Return t if the last non-comment, non-whitespace token of the
+Return non-nil if the last non-comment, non-whitespace token of the
 current line is the \"=>\" token (of an arrow function)."
   (let ((from (point)))
     (end-of-line)