From baf9cc50313bb7df94e8173349db9c834f1ccf64 Mon Sep 17 00:00:00 2001
From: Juan Manuel Macias <maciaschain@posteo.net>
Date: Fri, 11 Aug 2023 19:57:49 +0200
Subject: [PATCH] lisp/ox-latex.el: add the `:literal' attribute to verse
 block.

* (org-latex-verse-block): now the treatment of blank lines is
consistent with the syntax of the LaTeX `verse' environment, and the
one provided by the `verse' package. If the `':literal attribute is
used, the content is not exported within a `verse' environment, but as-is,
preserving horizontal spaces, line breaks, and blank lines.
---
 lisp/ox-latex.el | 52 ++++++++++++++++++++++++++++++++++++------------
 1 file changed, 39 insertions(+), 13 deletions(-)

diff --git a/lisp/ox-latex.el b/lisp/ox-latex.el
index 31cad1dc4..557ceee1b 100644
--- a/lisp/ox-latex.el
+++ b/lisp/ox-latex.el
@@ -4116,32 +4116,58 @@ contextual information."
   (let* ((lin (org-export-read-attribute :attr_latex verse-block :lines))
          (latcode (org-export-read-attribute :attr_latex verse-block :latexcode))
          (cent (org-export-read-attribute :attr_latex verse-block :center))
-         (attr (concat
-	        (if cent "[\\versewidth]" "")
-	        (if lin (format "\n\\poemlines{%s}" lin) "")
-	        (if latcode (format "\n%s" latcode) "")))
+         (lit (org-export-read-attribute :attr_latex verse-block :literal))
+         (attr (if (not lit)
+		   (concat
+		    (if cent "[\\versewidth]" "")
+		    (if lin (format "\n\\poemlines{%s}" lin) "")
+		    (if latcode (format "\n%s" latcode) ""))
+		 ""))
          (versewidth (org-export-read-attribute :attr_latex verse-block :versewidth))
-         (vwidth (if versewidth (format "\\settowidth{\\versewidth}{%s}\n" versewidth) ""))
-         (linreset (if lin "\n\\poemlines{0}" "")))
+         (vwidth (if (not lit)
+		     (if versewidth (format "\\settowidth{\\versewidth}{%s}\n" versewidth) "")
+		   ""))
+         (linreset (if (not lit)
+		       (if lin "\n\\poemlines{0}" "")
+		     "")))
     (concat
      (org-latex--wrap-label
       verse-block
       ;; In a verse environment, add a line break to each newline
       ;; character and change each white space at beginning of a line
-      ;; into a space of 1 em.  Also change each blank line with
-      ;; a vertical space of 1 em.
-      (format "%s\\begin{verse}%s\n%s\\end{verse}%s"
+      ;; into a normal space, calculated with `\fontdimen2\font'.
+      ;; One or more blank lines between lines are exported as a
+      ;; single blank line.  If the `:literal' attribute is used,
+      ;; CONTENTS is exported as is, with no environment, preserving
+      ;; line breaks and vertical and horizontal spaces.
+      (format (if (not lit)
+		  "%s\\begin{verse}%s\n%s\\end{verse}%s"
+		"%s%s\n%s%s")
 	      vwidth
 	      attr
 	      (replace-regexp-in-string
-	       "^[ \t]+" (lambda (m) (format "\\hspace*{%dem}" (length m)))
+	       "^[ \t]+" (lambda (m) (format "\\hspace*{%d\\fontdimen2\\font}" (length m)))
 	       (replace-regexp-in-string
-                (concat "^[ \t]*" (regexp-quote org-latex-line-break-safe) "$")
-	        "\\vspace*{1em}"
+                (if (not lit)
+		    (concat "\\("
+			    (regexp-quote org-latex-line-break-safe)
+			    "\n\\)"
+			    "\\(^[ \t]*"
+			    (regexp-quote org-latex-line-break-safe)
+			    "\n"
+			    "\\)+")
+		  (concat "^[ \t]*" (regexp-quote org-latex-line-break-safe) "$"))
+	        (if (not lit)
+		    (if lin "\\\\!\n\n" "\n\n")
+		  "\\vspace*{\\baselineskip}")
 	        (replace-regexp-in-string
 	         "\\([ \t]*\\\\\\\\\\)?[ \t]*\n"
                  (concat org-latex-line-break-safe "\n")
-	         contents nil t)
+	         (if (not lit)
+                     ;; Remove any blank lines before and after CONTENTS.
+                     (concat (org-trim contents t) "\n")
+		   contents)
+                 nil t)
                 nil t)
                nil t)
               linreset)
-- 
2.41.0