From faccc2182275354ebe7d85ac61dd753887b98315 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jean-Fran=C3=A7ois=20B?=
 <2589111+jfbu@users.noreply.github.com>
Date: Sat, 23 Jul 2022 12:42:33 +0200
Subject: [PATCH 1/2] Fix #10695: old LaTeX does not allow \@ifpackageloaded
 usage in body

---
 sphinx/texinputs/sphinx.sty                 | 21 +++++++++++++++++++++
 sphinx/texinputs/sphinxlatexadmonitions.sty |  2 +-
 sphinx/texinputs/sphinxlatexliterals.sty    |  2 +-
 sphinx/texinputs/sphinxlatexshadowbox.sty   |  2 +-
 sphinx/texinputs/sphinxpackageboxes.sty     | 16 ----------------
 5 files changed, 24 insertions(+), 19 deletions(-)

diff --git a/sphinx/texinputs/sphinx.sty b/sphinx/texinputs/sphinx.sty
index b1105515ba0..8e01c8ac24c 100644
--- a/sphinx/texinputs/sphinx.sty
+++ b/sphinx/texinputs/sphinx.sty
@@ -685,6 +685,27 @@
 %% FRAMED ENVIRONMENTS
 %
 \RequirePackage{sphinxpackageboxes}
+% This macro is possibly executed at begin document if the check
+% whether radii setting options have been used turns out positive
+\def\spx@RequirePackage@PictIIe{%
+\IfFileExists{pict2e.sty}
+   {\RequirePackage{pict2e}}
+   {\PackageWarningNoLine{sphinx}{%
+       The package pict2e is required for rounded boxes.\MessageBreak
+       It does not seem to be available on your system.\MessageBreak
+       Options for setting radii will thus be ignored}%
+    \AtEndDocument{\PackageWarningNoLine{sphinx}{%
+       I issued a warning which may have gotten lost in the\MessageBreak
+       gigantic console output: pict2e.sty was not found,\MessageBreak
+       and radii setting options have been ignored}}%
+    \def\spx@boxes@fcolorbox@rounded{\spx@boxes@fcolorbox}%
+   }%
+}%
+% This at begin document will be executed after \spx@RequirePackage@PictIIe
+\AtBeginDocument{%
+    \@ifpackageloaded{pict2e}{\let\spx@ifpackageloaded@pictiie\@firstoftwo}%
+                             {\let\spx@ifpackageloaded@pictiie\@secondoftwo}%
+}%
 \input{sphinxlatexadmonitions.sty}
 \input{sphinxlatexliterals.sty}
 \input{sphinxlatexshadowbox.sty}
diff --git a/sphinx/texinputs/sphinxlatexadmonitions.sty b/sphinx/texinputs/sphinxlatexadmonitions.sty
index 052de9bb0bf..d2a63daf271 100644
--- a/sphinx/texinputs/sphinxlatexadmonitions.sty
+++ b/sphinx/texinputs/sphinxlatexadmonitions.sty
@@ -162,7 +162,7 @@
           \ifdim\spx@boxes@radius@bottomleft >\z@0\fi
           1\spx@boxes@fcolorbox{##1}%
         \else
-          \@ifpackageloaded{pict2e}%
+          \spx@ifpackageloaded@pictiie
              {\ifspx@boxes@insetshadow
                 \spx@boxes@fcolorbox{##1}%
               \else
diff --git a/sphinx/texinputs/sphinxlatexliterals.sty b/sphinx/texinputs/sphinxlatexliterals.sty
index 35fc9ca9fb5..b7b01f7aa93 100644
--- a/sphinx/texinputs/sphinxlatexliterals.sty
+++ b/sphinx/texinputs/sphinxlatexliterals.sty
@@ -164,7 +164,7 @@
           \ifdim\spx@pre@radius@bottomleft >\z@0\fi
           1\spx@boxes@fcolorbox{\box\z@}%
         \else
-          \@ifpackageloaded{pict2e}%
+          \spx@ifpackageloaded@pictiie
              {\ifspx@pre@insetshadow
                 \spx@boxes@fcolorbox{\box\z@}%
               \else
diff --git a/sphinx/texinputs/sphinxlatexshadowbox.sty b/sphinx/texinputs/sphinxlatexshadowbox.sty
index d9a35eb56c8..069526717e6 100644
--- a/sphinx/texinputs/sphinxlatexshadowbox.sty
+++ b/sphinx/texinputs/sphinxlatexshadowbox.sty
@@ -79,7 +79,7 @@
           \ifdim\spx@topic@radius@bottomleft >\z@0\fi
           1\spx@boxes@fcolorbox{\box\z@}%
         \else
-          \@ifpackageloaded{pict2e}%
+          \spx@ifpackageloaded@pictiie
              {\ifspx@topic@insetshadow
                 \spx@boxes@fcolorbox{\box\z@}%
               \else
diff --git a/sphinx/texinputs/sphinxpackageboxes.sty b/sphinx/texinputs/sphinxpackageboxes.sty
index 1c1ec57ad36..c1438f84188 100644
--- a/sphinx/texinputs/sphinxpackageboxes.sty
+++ b/sphinx/texinputs/sphinxpackageboxes.sty
@@ -72,22 +72,6 @@
 % if nothing else is changed (perhaps in future the title itself could be also
 % rendered in a rounded box?)
 
-\def\spx@RequirePackage@PictIIe{%
-\IfFileExists{pict2e.sty}
-   {\RequirePackage{pict2e}}
-   {\PackageWarningNoLine{sphinx}{%
-       The package pict2e is required for rounded boxes.\MessageBreak
-       It does not seem to be available on your system.\MessageBreak
-       Options for setting radii will thus be ignored}%
-    \AtEndDocument{\PackageWarningNoLine{sphinx}{%
-       I issued a warning which may have gotten lost in the\MessageBreak
-       gigantic console output: pict2e.sty was not found,\MessageBreak
-       and radii setting options have been ignored}}%
-   \def\spx@boxes@fcolorbox@rounded{\spx@boxes@fcolorbox}%
-   }%
-}%
-
-
 %//// \spx@boxes@fcolorbox
 % This box will have the same baseline as its argument (which is typeset in
 % horizontal mode).  It takes into account four border widths parameters, four

From d1b4a75f4f09281af70a04fb405c126744c54651 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jean-Fran=C3=A7ois=20B?=
 <2589111+jfbu@users.noreply.github.com>
Date: Sat, 23 Jul 2022 13:03:48 +0200
Subject: [PATCH 2/2] LaTeX: fix another incompatibility with old pict2e LaTeX

We need to make sure the \put command arguments will expand to a
(fractional) number, so \strip@pt is added, and the \dimexpr properly
closed with \relax
---
 sphinx/texinputs/sphinxpackageboxes.sty | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/sphinx/texinputs/sphinxpackageboxes.sty b/sphinx/texinputs/sphinxpackageboxes.sty
index c1438f84188..72890feb150 100644
--- a/sphinx/texinputs/sphinxpackageboxes.sty
+++ b/sphinx/texinputs/sphinxpackageboxes.sty
@@ -362,16 +362,16 @@
      \dimexpr\dp\spx@tempboxa+\spx@boxes@padding@bottom+\spx@boxes@border\relax
      \hbox{%
    \begin{picture}%
-      % \strip@pt\dimexpr fot work around "old" LaTeX picture limitation
+      % \strip@pt\dimexpr to work around "old" LaTeX picture limitation
       % (we could use the "picture" package, this would add another dependency)
-      (\strip@pt\wd\spx@tempboxa,\strip@pt\dimexpr\ht\spx@tempboxa+\dp\spx@tempboxa)%
-      (\strip@pt\dimexpr-.5\spx@boxes@border,\strip@pt\dimexpr-.5\spx@boxes@border)%
+      (\strip@pt\wd\spx@tempboxa,\strip@pt\dimexpr\ht\spx@tempboxa+\dp\spx@tempboxa\relax)%
+      (\strip@pt\dimexpr-.5\spx@boxes@border\relax,\strip@pt\dimexpr-.5\spx@boxes@border\relax)%
 \ifspx@boxes@withshadow
               \color{spx@boxes@shadowcolor}%
-              \put(\dimexpr\ifdim\spx@boxes@shadow@xoffset<\z@-\fi
-                           0.5\spx@boxes@border+\spx@boxes@shadow@xoffset,%
-                   \dimexpr\ifdim\spx@boxes@shadow@yoffset<\z@\else-\fi
-                           0.5\spx@boxes@border-\spx@boxes@shadow@yoffset)
+              \put(\strip@pt\dimexpr\ifdim\spx@boxes@shadow@xoffset<\z@-\fi
+                           0.5\spx@boxes@border+\spx@boxes@shadow@xoffset\relax,%
+                   \strip@pt\dimexpr\ifdim\spx@boxes@shadow@yoffset<\z@\else-\fi
+                           0.5\spx@boxes@border-\spx@boxes@shadow@yoffset\relax)
                    {\spx@boxes@borderpath\fillpath}%
               {\ifspx@boxes@withbackgroundcolor\else
                    \color{white}% or rather try to use page color?