Merge branch 'bidi-isolate' into 'master'

Isolate bidi directionality changes to a single text.

See merge request lyskom-elisp-client/lyskom-elisp-client!15

src/ChangeLog

+2020-09-04  Per Cederqvist  <ceder@lysator.liu.se>
+
+	Isolate bidi directionality changes to a single text.
+	* view-text.el (lyskom-print-text): Insert a paragraph separator
+	if the bidi directionality was changed by the text.
+
 2020-08-17  Per Cederqvist  <ceder@lysator.liu.se>
 
 	Emacs 27.1 compatibility.

src/view-text.el

@@ -882,7 +882,8 @@ Mark the text as read if (and only if) MARK-AS-READ is non-nil.
 Args: TEXT-STAT TEXT MARK-AS-READ TEXT-NO FLAT-REVIEW."
   (let* ((lyskom-current-function 'lyskom-print-text)
          (cti (lyskom-get-aux-item (text-stat->aux-items text-stat) 1))
-         (content-type (and cti (aux-item->data (car cti)))))
+         (content-type (and cti (aux-item->data (car cti))))
+         (bidi-at-start (current-bidi-paragraph-direction)))
     (cond
      ((or (null text)
           (null text-stat))
@@ -1011,6 +1012,23 @@ Args: TEXT-STAT TEXT MARK-AS-READ TEXT-NO FLAT-REVIEW."
                (when kom-highlight-dashed-lines
                  `(face ,(or kom-dashed-lines-face
                              lyskom-default-dashed-lines-face)))))))
+
+        ;; If the last paragraph of the text has a different bidi
+        ;; direction than the default bidi direction in this buffer,
+        ;; insert a newline so that the rest of the buffer will get
+        ;; its direction from the prompt.
+	;;
+	;; Perhaps it would be more correct to always insert a newline
+	;; before the text and after the text, so that the text always
+        ;; has a bidi direction that is independent from the bidi
+        ;; direction of the prompts, headers and footers, but that
+        ;; would be too large a departure from the classical layout of
+        ;; a LysKOM buffer.  If there were an invisible way to specify
+        ;; a paragraph break at those positions, that would be nice.
+        ;; For now, we live with this workaround.
+        (unless (eq (current-bidi-paragraph-direction) bidi-at-start)
+          (insert "\n"))
+
         (if mark-as-read
             (lyskom-mark-as-read text-stat))
         (setq lyskom-previous-text lyskom-current-text)