Re: Line breaks and brackets in LaTeX export

[Ihor Radchenko]

Juan Manuel Macías <maciaschain@posteo.net> writes:

>> It is easy to change \\\empty constant to \\[0pt] if necessary. I have
>> no objection either way. Though I do not feel like we are in rush. I'd
>> like to hear from ox-latex maintainer.
>
> Today I have tried with the latest version of tabularray (2022C, the one
> I tried yesterday was 2022A, included in TeX Live 2022), and the bad
> results persist. Also, it now returns a compile error when an \empty
> precedes a \hline. I suspect this package does a pretty drastic
> redefinition of \\. The [0pt] option still works fine here, though.

Then [0pt] should it be. At least for now, before we have a cleaner
solution.

See the attached patch.

>From b060f63078d65758f8fd2ab7725fbcf8b2de0057 Mon Sep 17 00:00:00 2001
Message-Id: 
<b060f63078d65758f8fd2ab7725fbcf8b2de0057.1666151751.git.yantar92@posteo.net>
From: Ihor Radchenko <yantar92@posteo.net>
Date: Wed, 19 Oct 2022 11:48:26 +0800
Subject: [PATCH] org-latex-line-break-safe: Use safer value of "\\[0pt]"
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

* lisp/ox-latex.el (org-latex-line-break-safe):
(org-latex-table-row):
Change \empty ending to explicit optional argument.  \empty still has
undesired side effects in some cases.

* testing/lisp/test-org-table.el (test-org-table/to-latex):
* testing/lisp/test-ox-latex.el (test-ox-latex/verse): Update tests.

Reported-by: Juan Manuel Macías <maciaschain@posteo.net>
Link: 87o7u9rz1a.fsf@posteo.net">https://orgmode.org/list/87o7u9rz1a.fsf@posteo.net
---
 lisp/ox-latex.el               | 12 ++++++------
 testing/lisp/test-org-table.el |  6 +++---
 testing/lisp/test-ox-latex.el  | 12 ++++++------
 3 files changed, 15 insertions(+), 15 deletions(-)

diff --git a/lisp/ox-latex.el b/lisp/ox-latex.el
index dc8477d14..a5652fd78 100644
--- a/lisp/ox-latex.el
+++ b/lisp/ox-latex.el
@@ -278,17 +278,17 @@ (defconst org-latex-language-alist
 
 - `:lang-name' the actual name of the language.")
 
-(defconst org-latex-line-break-safe "\\\\\\empty"
+(defconst org-latex-line-break-safe "\\\\[0pt]"
   "Linebreak protecting the following [...].
 
-Without \"\\empty\" it would be interpreted as an optional argument to
+Without \"[0pt]\" it would be interpreted as an optional argument to
 the \\\\.
 
 This constant, for example, makes the below code not err:
 
 \\begin{tabular}{c|c}
-    [t] & s\\\\\\empty
-    [I] & A\\\\\\empty
+    [t] & s\\\\[0pt]
+    [I] & A\\\\[0pt]
     [m] & kg
 \\end{tabular}")
 
@@ -4005,9 +4005,9 @@ (defun org-latex-table-row (table-row contents info)
                              (org-export-get-parent-table table-row) info))))
           (format "%s
 \\endfirsthead
-\\multicolumn{%d}{l}{%s} \\\\\\empty
+\\multicolumn{%d}{l}{%s} \\\\[0pt]
 %s
-%s \\\\\\empty\n
+%s \\\\[0pt]\n
 %s
 \\endhead
 %s\\multicolumn{%d}{r}{%s} \\\\
diff --git a/testing/lisp/test-org-table.el b/testing/lisp/test-org-table.el
index 722c37ea4..573179878 100644
--- a/testing/lisp/test-org-table.el
+++ b/testing/lisp/test-org-table.el
@@ -1635,11 +1635,11 @@ (ert-deftest test-org-table/to-generic ()
 (ert-deftest test-org-table/to-latex ()
   "Test `orgtbl-to-latex' specifications."
   (should
-   (equal "\\begin{tabular}{l}\na\\\\\\empty\n\\end{tabular}"
+   (equal "\\begin{tabular}{l}\na\\\\[0pt]\n\\end{tabular}"
          (orgtbl-to-latex (org-table-to-lisp "| a |") nil)))
   ;; Test :environment parameter.
   (should
-   (equal "\\begin{tabularx}{l}\na\\\\\\empty\n\\end{tabularx}"
+   (equal "\\begin{tabularx}{l}\na\\\\[0pt]\n\\end{tabularx}"
          (orgtbl-to-latex (org-table-to-lisp "| a |")
                           '(:environment "tabularx"))))
   ;; Test :booktabs parameter.
@@ -1648,7 +1648,7 @@ (ert-deftest test-org-table/to-latex ()
     "\\toprule" (orgtbl-to-latex (org-table-to-lisp "| a |") '(:booktabs t))))
   ;; Handle LaTeX snippets.
   (should
-   (equal "\\begin{tabular}{l}\n\\(x\\)\\\\\\empty\n\\end{tabular}"
+   (equal "\\begin{tabular}{l}\n\\(x\\)\\\\[0pt]\n\\end{tabular}"
          (orgtbl-to-latex (org-table-to-lisp "| $x$ |") nil)))
   ;; Test pseudo objects and :raw parameter.
   (should
diff --git a/testing/lisp/test-ox-latex.el b/testing/lisp/test-ox-latex.el
index 4fb9f2888..adb3a60ea 100644
--- a/testing/lisp/test-ox-latex.el
+++ b/testing/lisp/test-ox-latex.el
@@ -60,14 +60,14 @@ (ert-deftest test-ox-latex/verse ()
     (should
      (search-forward
       "\\begin{verse}
-lorem ipsum dolor\\\\\\empty
-lorem ipsum dolor\\\\\\empty
+lorem ipsum dolor\\\\[0pt]
+lorem ipsum dolor\\\\[0pt]
 \\vspace*{1em}
-lorem ipsum dolor\\\\\\empty
-lorem ipsum dolor\\\\\\empty
+lorem ipsum dolor\\\\[0pt]
+lorem ipsum dolor\\\\[0pt]
 \\vspace*{1em}
-lorem ipsum dolor\\\\\\empty
-lorem ipsum dolor\\\\\\empty
+lorem ipsum dolor\\\\[0pt]
+lorem ipsum dolor\\\\[0pt]
 \\end{verse}"))))
 
 (provide 'test-ox-latex)
-- 
2.35.1


-- 
Ihor Radchenko // yantar92,
Org mode contributor,
Learn more about Org mode at <https://orgmode.org/>.
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