Fix creating imenu index when there is no level1 header

CHANGES.md

@@ -33,6 +33,7 @@
     -   Fix wrong fontification words between strong markups [GH-534][]
     -   Fix wrong italic fontification just after code block [GH-548][]
     -   Fix too indended list face issue [GH-569][]
+    -   Fix creating imenu index issue when there is no level-1 header too[GH-571][]
 
   [gh-290]: https://github.com/jrblevin/markdown-mode/issues/290
   [gh-311]: https://github.com/jrblevin/markdown-mode/issues/311
@@ -52,7 +53,8 @@
   [gh-548]: https://github.com/jrblevin/markdown-mode/issues/548
   [gh-553]: https://github.com/jrblevin/markdown-mode/issues/553
   [gh-560]: https://github.com/jrblevin/markdown-mode/issues/560
-  [gh-560]: https://github.com/jrblevin/markdown-mode/issues/569
+  [gh-569]: https://github.com/jrblevin/markdown-mode/issues/569
+  [gh-571]: https://github.com/jrblevin/markdown-mode/issues/571
 
 # Markdown Mode 2.4
 

markdown-mode.el

@@ -5533,52 +5533,61 @@ See also `markdown-mode-map'.")
   "Create and return a nested imenu index alist for the current buffer.
 See `imenu-create-index-function' and `imenu--index-alist' for details."
   (let* ((root '(nil . nil))
-         cur-alist
-         (cur-level 0)
-         (empty-heading "-")
-         (self-heading ".")
-         hashes pos level heading)
+         (min-level 9999)
+         hashes headers)
     (save-excursion
       ;; Headings
       (goto-char (point-min))
       (while (re-search-forward markdown-regex-header (point-max) t)
-        (unless (markdown-code-block-at-point-p)
+        (unless (or (markdown-code-block-at-point-p)
+                    (and (match-beginning 3)
+                         (get-text-property (match-beginning 3) 'markdown-yaml-metadata-end)))
           (cond
            ((match-string-no-properties 2) ;; level 1 setext
-            (setq heading (match-string-no-properties 1))
-            (setq pos (match-beginning 1)
-                  level 1))
+            (setq min-level 1)
+            (push (list :heading (match-string-no-properties 1)
+                        :point (match-beginning 1)
+                        :level 1) headers))
            ((match-string-no-properties 3) ;; level 2 setext
-            (setq heading (match-string-no-properties 1))
-            (setq pos (match-beginning 1)
-                  level 2))
+            (setq min-level (min min-level 2))
+            (push (list :heading (match-string-no-properties 1)
+                        :point (match-beginning 1)
+                        :level (- 2 (1- min-level))) headers))
            ((setq hashes (markdown-trim-whitespace
                           (match-string-no-properties 4)))
-            (setq heading (match-string-no-properties 5)
-                  pos (match-beginning 4)
-                  level (length hashes))))
-          (let ((alist (list (cons heading pos))))
-            (cond
-             ((= cur-level level)       ; new sibling
-              (setcdr cur-alist alist)
-              (setq cur-alist alist))
-             ((< cur-level level)       ; first child
-              (dotimes (_ (- level cur-level 1))
-                (setq alist (list (cons empty-heading alist))))
-              (if cur-alist
-                  (let* ((parent (car cur-alist))
-                         (self-pos (cdr parent)))
-                    (setcdr parent (cons (cons self-heading self-pos) alist)))
-                (setcdr root alist))    ; primogenitor
-              (setq cur-alist alist)
-              (setq cur-level level))
-             (t                         ; new sibling of an ancestor
-              (let ((sibling-alist (last (cdr root))))
-                (dotimes (_ (1- level))
-                  (setq sibling-alist (last (cdar sibling-alist))))
-                (setcdr sibling-alist alist)
-                (setq cur-alist alist))
-              (setq cur-level level))))))
+            (setq min-level (min min-level (length hashes)))
+            (push (list :heading (match-string-no-properties 5)
+                        :point (match-beginning 4)
+                        :level (- (length hashes) (1- min-level))) headers)))))
+      (cl-loop with cur-level = 0
+               with cur-alist = nil
+               with empty-heading = "-"
+               with self-heading = "."
+               for header in (reverse headers)
+               for level = (plist-get header :level)
+               do
+               (let ((alist (list (cons (plist-get header :heading) (plist-get header :point)))))
+                 (cond
+                  ((= cur-level level)  ; new sibling
+                   (setcdr cur-alist alist)
+                   (setq cur-alist alist))
+                  ((< cur-level level)  ; first child
+                   (dotimes (_ (- level cur-level 1))
+                     (setq alist (list (cons empty-heading alist))))
+                   (if cur-alist
+                       (let* ((parent (car cur-alist))
+                              (self-pos (cdr parent)))
+                         (setcdr parent (cons (cons self-heading self-pos) alist)))
+                     (setcdr root alist)) ; primogenitor
+                   (setq cur-alist alist)
+                   (setq cur-level level))
+                  (t                    ; new sibling of an ancestor
+                   (let ((sibling-alist (last (cdr root))))
+                     (dotimes (_ (1- level))
+                       (setq sibling-alist (last (cdar sibling-alist))))
+                     (setcdr sibling-alist alist)
+                     (setq cur-alist alist))
+                   (setq cur-level level)))))
       ;; Footnotes
       (let ((fn (markdown-get-defined-footnotes)))
         (if (or (zerop (length fn))

tests/markdown-test.el

@@ -6510,6 +6510,26 @@ https://github.com/jrblevin/markdown-mode/issues/235"
       (should-not (member "^fn1" entries))
       (should-not (member "^fn2" entries)))))
 
+(ert-deftest test-markdown-imenu/no-level-one-header ()
+  "Create imenu entries if there is no level-1 header
+https://github.com/jrblevin/markdown-mode/issues/571"
+  (markdown-test-string "---
+title: Wat
+---
+
+## Section a
+
+### Sub 1
+
+### Sub 11
+
+## Section b
+
+### Sub 2"
+    (let ((entries (markdown-imenu-create-nested-index)))
+      (should (string= (car (nth 0 entries)) "Section a"))
+      (should (string= (car (nth 1 entries)) "Section b")))))
+
 (ert-deftest test-markdown-command/function ()
   "Test ‘markdown’ with ‘markdown-command’ being a function."
   (markdown-test-string "foo"