[latex3-commits] [git/LaTeX3-latex3-latex2e] gh501: avoid infinite loop on math alphabet error #501 (6277aa3b)

[David Carlisle]

Repository : https://github.com/latex3/latex2e
On branch  : gh501
Link       : https://github.com/latex3/latex2e/commit/6277aa3b3636e729d303883b540cb2172367eb87

>---------------------------------------------------------------

commit 6277aa3b3636e729d303883b540cb2172367eb87
Author: David Carlisle <d.p.carlisle at gmail.com>
Date:   Mon Feb 15 12:08:10 2021 +0000

    avoid infinite loop on math alphabet error #501


>---------------------------------------------------------------

6277aa3b3636e729d303883b540cb2172367eb87
 base/changes.txt                                |  5 +++++
 base/ltfssdcl.dtx                               |  8 ++++++--
 base/testfiles/github-0501.lvt                  | 14 ++++++++++++++
 base/testfiles/{tlb0483.tlg => github-0501.tlg} |  8 +++-----
 4 files changed, 28 insertions(+), 7 deletions(-)

diff --git a/base/changes.txt b/base/changes.txt
index 1424800a..67f9c839 100644
--- a/base/changes.txt
+++ b/base/changes.txt
@@ -6,6 +6,11 @@ completeness or accuracy and it contains some references to files that
 are not part of the distribution.
 ================================================================================
 
+2021-02-15  David Carlisle  <David.Carlisle at latex-project.org>
+
+	* ltfssdcl.dtx: two additional \expandafter to avoid infinite
+	loop on not in math error. (gh/501)
+
 2021-02-11  Frank Mittelbach  <Frank.Mittelbach at latex-project.org>
 
 	* classes.dtx (subsubsection{Itemize}):
diff --git a/base/ltfssdcl.dtx b/base/ltfssdcl.dtx
index dd4e14fa..9710d543 100644
--- a/base/ltfssdcl.dtx
+++ b/base/ltfssdcl.dtx
@@ -36,7 +36,7 @@
 %
 %
 \ProvidesFile{ltfssdcl.dtx}
-            [2021/01/15 v3.0v LaTeX Kernel (NFSS Declarative Interface)]
+            [2021/02/15 v3.0w LaTeX Kernel (NFSS Declarative Interface)]
 % \iffalse
 \documentclass{ltxdoc}
 \begin{document}
@@ -490,7 +490,11 @@
                    in version \math at version}%
         \@eha
   \fi
- \else \expandafter\non at alpherr\fi
+%    \end{macrocode}
+% extra \cs{expandafter} to remove the \cs{expandafter} added below
+% \changes{v3.0w}{2021/02/115}{fix for (gh/501)}
+%    \begin{macrocode}
+ \else \expandafter\expandafter\expandafter\non at alpherr\fi
 %    \end{macrocode}
 %    If the legacy interface is used, e.g., \verb=$\sf -1$= the math
 %    alphabet \verb=#1= does not take an argument so we better do not
diff --git a/base/testfiles/github-0501.lvt b/base/testfiles/github-0501.lvt
new file mode 100644
index 00000000..9ad2a9b0
--- /dev/null
+++ b/base/testfiles/github-0501.lvt
@@ -0,0 +1,14 @@
+\documentclass{article}
+
+\input{test2e}
+
+\begin{document}
+
+\START
+
+% should give a single error on \mathit
+% not loop errors on \expandafter
+
+\mathit{x}
+
+\END
\ No newline at end of file
diff --git a/base/testfiles/tlb0483.tlg b/base/testfiles/github-0501.tlg
similarity index 69%
copy from base/testfiles/tlb0483.tlg
copy to base/testfiles/github-0501.tlg
index 282221a9..ee87539b 100644
--- a/base/testfiles/tlb0483.tlg
+++ b/base/testfiles/github-0501.tlg
@@ -1,11 +1,9 @@
 This is a generated file for the LaTeX2e validation system.
 Don't change this file in any respect.
-! LaTeX Error: Counter too large.
+! LaTeX Error: \mathit allowed only in math mode.
 See the LaTeX manual or LaTeX Companion for explanation.
 Type  H <return>  for immediate help.
  ...                                              
-l. ...\section{ccc}
-You've lost some text.  Try typing  <return>  to proceed.
+l. ...\mathit{x}
+You're in trouble here.  Try typing  <return>  to proceed.
 If that doesn't work, type  X <return>  to quit.
-[1
-] (tlb0483.aux)