ox-html: Control wrapping of source lines

* lisp/ox-html.el (org-html-format-code, org-html-do-format-code):
  Use new export option :html-wrap-src-lines with variable
  org-html-wrap-src-lines to control whether source code lines should
  be wrapped in code elements or not.
* doc/org-manual.org: Document the new option

doc/org-manual.org

@@ -10789,7 +10789,7 @@ environments and math templates.  Inside Org mode, you can make use of
 some of the features of CDLaTeX mode.  You need to install
 =cdlatex.el= and =texmathp.el= (the latter comes also with AUCTeX)
 using [[https://melpa.org/][MELPA]] with the [[https://www.gnu.org/software/emacs/manual/html_node/emacs/Package-Installation.html][Emacs packaging system]] or alternatively from
-[[https://staff.fnwi.uva.nl/c.dominik/Tools/cdlatex/]].  Do not use 
+[[https://staff.fnwi.uva.nl/c.dominik/Tools/cdlatex/]].  Do not use
 CDLaTeX mode itself under Org mode, but use the special version Org
 CDLaTeX minor mode that comes as part of Org.  Turn it on for the
 current buffer with {{{kbd(M-x org-cdlatex-mode)}}}, or for all Org
@@ -15753,6 +15753,7 @@ Settings]]), however, override everything.
 | ~:html-use-infojs~                             | ~org-html-use-infojs~                             |
 | ~:html-validation-link~                        | ~org-html-validation-link~                        |
 | ~:html-viewport~                               | ~org-html-viewport~                               |
+| ~:html-wrap-src-lines~                         | ~org-html-wrap-src-lines~                         |
 | ~:html-xml-declaration~                        | ~org-html-xml-declaration~                        |
 
 **** LaTeX specific properties

lisp/ox-html.el

@@ -172,6 +172,7 @@
     (:html-table-row-open-tag nil nil org-html-table-row-open-tag)
     (:html-table-row-close-tag nil nil org-html-table-row-close-tag)
     (:html-xml-declaration nil nil org-html-xml-declaration)
+    (:html-wrap-src-lines nil nil org-html-wrap-src-lines)
     (:html-klipsify-src nil nil org-html-klipsify-src)
     (:html-klipse-css nil nil org-html-klipse-css)
     (:html-klipse-js nil nil org-html-klipse-js)
@@ -932,6 +933,15 @@ in all modes you want.  Then, use the command
   :group 'org-export-html
   :type 'string)
 
+(defcustom org-html-wrap-src-lines nil
+  "If non-nil, wrap individual lines of source blocks in \"code\" elements.
+In this case, add line number in attribute \"data-ox-html-linenr\" when line
+numbers are enabled."
+  :group 'org-export-html
+  :package-version '(Org . "9.3")
+  :type 'boolean
+  :safe t)
+
 ;;;; Table
 
 (defcustom org-html-table-default-attributes
@@ -2231,14 +2241,15 @@ is the language used for CODE, as a string, or nil."
 	    (if (and beg end) (substring code beg end) code)))))))))
 
 (defun org-html-do-format-code
-  (code &optional lang refs retain-labels num-start)
+  (code &optional lang refs retain-labels num-start wrap-lines)
   "Format CODE string as source code.
-Optional arguments LANG, REFS, RETAIN-LABELS and NUM-START are,
-respectively, the language of the source code, as a string, an
+Optional arguments LANG, REFS, RETAIN-LABELS, NUM-START, WRAP-LINES
+are, respectively, the language of the source code, as a string, an
 alist between line numbers and references (as returned by
 `org-export-unravel-code'), a boolean specifying if labels should
-appear in the source code, and the number associated to the first
-line of code."
+appear in the source code, the number associated to the first
+line of code, and a boolean specifying if lines of code should be
+wrapped in code elements."
   (let* ((code-lines (split-string code "\n"))
 	 (code-length (length code-lines))
 	 (num-fmt
@@ -2256,11 +2267,13 @@ line of code."
 		(format "<span class=\"linenr\">%s</span>"
 			(format num-fmt line-num)))
 	      ;; Transcoded src line.
-	      (format "<code%s>%s</code>"
-                      (if num-start
-                          (format " data-ox-html-linenr=\"%s\"" line-num)
-                        "")
-                      loc)
+	      (if wrap-lines
+		  (format "<code%s>%s</code>"
+			  (if num-start
+                              (format " data-ox-html-linenr=\"%s\"" line-num)
+                            "")
+			  loc)
+		loc)
 	      ;; Add label, if needed.
 	      (when (and ref retain-labels) (format " (%s)" ref))))
        ;; Mark transcoded line as an anchor, if needed.
@@ -2281,8 +2294,10 @@ used as a communication channel."
 	 ;; Does the source block contain labels?
 	 (retain-labels (org-element-property :retain-labels element))
 	 ;; Does it have line numbers?
-	 (num-start (org-export-get-loc element info)))
-    (org-html-do-format-code code lang refs retain-labels num-start)))
+	 (num-start (org-export-get-loc element info))
+	 ;; Should lines be wrapped in code elements?
+	 (wrap-lines (plist-get info :html-wrap-src-lines)))
+    (org-html-do-format-code code lang refs retain-labels num-start wrap-lines)))
 
 
 ;;; Tables of Contents