org-hugo--heading-get-slug: Parse the #+hugo_section keyword too

Also add a new optional arg `inherit-export-file-name`.

ox-hugo.el

@@ -1890,7 +1890,7 @@ This function will never return nil."
                    "")))
     (substring (md5 title) 0 hash-len)))
 
-(defun org-hugo--heading-get-slug (heading _info)
+(defun org-hugo--heading-get-slug (heading info &optional inherit-export-file-name)
   "Return the slug string derived from an Org HEADING element.
 
 1. If HEADING has `:EXPORT_FILE_NAME' and `:EXPORT_HUGO_SLUG'
@@ -1908,11 +1908,16 @@ This function will never return nil."
    is neither \"index\" nor \"_index\", use that to derive the
    slug.
 
-The `:EXPORT_HUGO_SECTION' property is prepended to all of the
-above options.
+If INHERIT-EXPORT-FILE-NAME is non-nil, allow inheriting the
+`:EXPORT_FILE_NAME' property from a parent subtree.
+
+The `:EXPORT_HUGO_SECTION' property or `#+hugo_section' keyword
+value is prepended to all of the above options.
+
+INFO is a plist used as a communication channel.
 
 Return nil if none of the above are true."
-  (let ((file (org-string-nw-p (org-export-get-node-property :EXPORT_FILE_NAME heading)))
+  (let ((file (org-string-nw-p (org-export-get-node-property :EXPORT_FILE_NAME heading inherit-export-file-name)))
         hugo-slug bundle slug)
     ;; (message "[org-hugo--heading-get-slug DBG] EXPORT_FILE_NAME: %S" file)
     (when file
@@ -1950,7 +1955,9 @@ Return nil if none of the above are true."
       (when slug
         (let ((pheading heading)
               section fragment fragments)
-          (setq section (org-string-nw-p (org-export-get-node-property :EXPORT_HUGO_SECTION heading :inherited)))
+          (setq section (org-string-nw-p
+                         (or (org-export-get-node-property :EXPORT_HUGO_SECTION heading :inherited)
+                             (plist-get info :hugo-section))))
 
           ;; Iterate over all parents of heading, and collect section
           ;; path fragments.

test/ert/org-test-lib.el

@@ -56,7 +56,7 @@ variable, and communication channel under `info'."
      (let* ((tree (org-element-parse-buffer))
             (info (org-combine-plists
                    (org-export--get-export-attributes)
-                   (org-export-get-environment))))
+                   (org-export-get-environment 'hugo))))
        (org-export--prune-tree tree info)
        (org-export--remove-uninterpreted-data tree info)
        (let ((info (org-combine-plists

test/ert/tslug.el

@@ -212,6 +212,21 @@
              (let ((el (org-element-at-point)))
                (org-hugo--heading-get-slug el info))))))
 
+;; Section
+(ert-deftest test-slug/section ()
+
+  ;; Section keyword
+  (should
+   (string= "section/file"
+            (org-test-with-parsed-data
+             "#+hugo_section: section
+* Some Heading<point>
+:PROPERTIES:
+:EXPORT_FILE_NAME: file
+:END:"
+             (let ((el (org-element-at-point)))
+               (org-hugo--heading-get-slug el info))))))
+
 ;; Section fragments
 (ert-deftest test-slug/section-fragments ()