[PATCH] ox-latex: Allow percent sign in 'src-block' caption

[Maxim Nikulin <manikulin@gmail.com>]

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On 03/09/2021 19:17, Maxim Nikulin wrote:
> On 30/07/2021 22:00, Charest, Luc wrote:
>>
>> org-latex-src-block: Not enough arguments for format string
> 
> Confirmed
> 
> User input is combined with format string in `org-latex-src-block'
> so percent character in caption is treated as a format specifier.> Maybe emacs versions newer than 26 does not throw an error
> on extra specifier with missed argument. =:latex-cation-above nil=
> might still cause corrupted LaTeX code.

I have decided that it is better to provide a partial fix than to leave
the problem as is.  This patch covers only plain verbatim environment,
more advanced formatting using listings or minted should be addressed
by another change (Anybody?).  Do not close the bug after applying
this patch.

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From 5e6930e3c3d30f13e6e33a6fc504b445cacc579d Mon Sep 17 00:00:00 2001
In-Reply-To: <sgt3om$mae$1@ciao.gmane.io>
References: <sgt3om$mae$1@ciao.gmane.io>
From: Max Nikulin <manikulin@gmail.com>
Date: Tue, 7 Sep 2021 19:01:11 +0700
Subject: [PATCH] ox-latex: Allow percent sign in 'src-block' caption

* lisp/ox-latex.el (org-latex-src-block): Prevent leak of percent sign
from caption to `format' first argument causing export failure due to
insufficient argument number.  The fix covers only the case of verbatim
environment.
* testing/lisp/test-ox.el
(test-org-export/latex-src-block-verbatim-caption): New test for src
block LaTeX export with cases of various formatting of caption and
verbatim environment.  Check that percent signs in caption and source
block body do not lead to errors.

Reported-by: Charest, Luc <charest.luc@hydroquebec.com>
<https://lists.gnu.org/archive/html/emacs-orgmode/2021-08/msg00017.html>
---
 lisp/ox-latex.el        | 30 ++++++-------
 testing/lisp/test-ox.el | 97 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 111 insertions(+), 16 deletions(-)

diff --git a/lisp/ox-latex.el b/lisp/ox-latex.el
index 99076f8b9..b325b8892 100644
--- a/lisp/ox-latex.el
+++ b/lisp/ox-latex.el
@@ -2994,22 +2994,20 @@ contextual information."
       (cond
        ;; Case 1.  No source fontification.
        ((or (not lang) (not listings))
-	(let* ((caption-str (org-latex--caption/label-string src-block info))
-	       (float-env
-		(cond ((string= "multicolumn" float)
-		       (format "\\begin{figure*}[%s]\n%s%%s\n%s\\end{figure*}"
-			       (plist-get info :latex-default-figure-position)
-			       (if caption-above-p caption-str "")
-			       (if caption-above-p "" caption-str)))
-		      (caption (concat
-				(if caption-above-p caption-str "")
-				"%s"
-				(if caption-above-p "" (concat "\n" caption-str))))
-		      (t "%s"))))
-	  (format
-	   float-env
-	   (concat (format "\\begin{verbatim}\n%s\\end{verbatim}"
-			   (org-export-format-code-default src-block info))))))
+	(let ((caption-str (org-latex--caption/label-string src-block info))
+              (verbatim (format "\\begin{verbatim}\n%s\\end{verbatim}"
+                                (org-export-format-code-default src-block info))))
+          (cond ((string= "multicolumn" float)
+                 (format "\\begin{figure*}[%s]\n%s%s\n%s\\end{figure*}"
+                         (plist-get info :latex-default-figure-position)
+                         (if caption-above-p caption-str "")
+                         verbatim
+                         (if caption-above-p "" caption-str)))
+                (caption (concat
+                          (if caption-above-p caption-str "")
+                          verbatim
+                          (if caption-above-p "" (concat "\n" caption-str))))
+                (t verbatim))))
        ;; Case 2.  Custom environment.
        (custom-env
 	(let ((caption-str (org-latex--caption/label-string src-block info))
diff --git a/testing/lisp/test-ox.el b/testing/lisp/test-ox.el
index 3f39645af..54558041b 100644
--- a/testing/lisp/test-ox.el
+++ b/testing/lisp/test-ox.el
@@ -3907,6 +3907,103 @@ Another text. (ref:text)
 	      (org-export-format-code-default
 	       (org-element-map tree 'src-block #'identity info t) info))))))
 
+(ert-deftest test-org-export/latex-src-block-verbatim-caption ()
+  "Test `org-latex-src-block' caption for verbatim environment.
+Check that percent sign does not become a part of format.
+This test does not cover listings and custom environments."
+  (let ((export
+	 (lambda (buffer-text)
+	   (org-test-with-parsed-data
+	       buffer-text
+	     (let* ((backend (org-export-get-backend 'latex))
+		    (info (org-combine-plists
+			   (org-export--get-export-attributes backend)
+			   (org-export-get-environment backend)))
+		    (result (org-latex-src-block
+			     (org-element-map tree 'src-block #'identity info t)
+			     t info)))
+	       ;; Remove properties to make failure reports more clear.
+	       (set-text-properties 0 (length result) nil result)
+	       result)))))
+
+    (should (equal
+	     "\
+\\begin{verbatim}
+\"No float, no listings, 20%S\"
+\\end{verbatim}
+\\captionof{figure}{Caption of verbatim is below, 20\\%s}
+"
+	     (funcall export
+		      "\
+#+CAPTION: Caption of verbatim is below, 20%s
+#+BEGIN_SRC emacs-lisp
+  \"No float, no listings, 20%S\"
+#+END_SRC")))
+
+    ;; `org-latex-caption-above' has no associated property or keyword.
+    (should (equal
+	     "\
+\\captionof{figure}{Caption of verbatim is above, 40\\%s}
+\\begin{verbatim}
+\"No float, no listings, 40%S\"
+\\end{verbatim}"
+	     (let ((org-latex-caption-above t))
+	       (funcall export
+			"\
+#+CAPTION: Caption of verbatim is above, 40%s
+#+BEGIN_SRC emacs-lisp
+  \"No float, no listings, 40%S\"
+#+END_SRC"))))
+
+    (should (equal
+	     "\
+\\begin{figure*}[tp]
+\\caption{Caption is above, 60\\%s}
+\\begin{verbatim}
+\"Float, no listings, 60%S\"
+\\end{verbatim}
+\\end{figure*}"
+	     (let ((org-latex-caption-above t)
+		   (org-latex-default-figure-position "tp"))
+	       (funcall export
+			"\
+#+CAPTION: Caption is above, 60%s
+#+ATTR_LATEX: :float multicolumn
+#+BEGIN_SRC emacs-lisp
+  \"Float, no listings, 60%S\"
+#+END_SRC"))))
+
+    (should (equal
+	     "\
+\\begin{figure*}[tp]
+\\begin{verbatim}
+\"Float, no lang, listings, 80%S\"
+\\end{verbatim}
+\\caption{Caption is below, 60\\%s}
+\\end{figure*}"
+	     (let ((org-latex-listings 'minted) ; inactive due to missing lang
+		   (org-latex-default-figure-position "tp"))
+	       ;; Namely "multicolumn" value to get just figure environment
+	       ;; looks like a bug.
+	       (funcall export
+			"\
+#+CAPTION: Caption is below, 60%s
+#+ATTR_LATEX: :float multicolumn
+#+BEGIN_SRC
+  \"Float, no lang, listings, 80%S\"
+#+END_SRC"))))
+
+    (should (equal
+	     "\
+\\begin{verbatim}
+\"No caption, no float, no listings, 100%S\"
+\\end{verbatim}"
+	     (funcall export
+		      "\
+#+BEGIN_SRC emacs-lisp
+  \"No caption, no float, no listings, 100%S\"
+#+END_SRC")))))
+
 
 \f
 ;;; Smart Quotes
-- 
2.25.1