From e718935b3374c9fa519059cdbb27e087edf7dfad Mon Sep 17 00:00:00 2001
From: Thomas Wucher <thomas.wucher@gtd-gmbh.de>
Date: Tue, 3 Nov 2020 15:40:55 +0100
Subject: [PATCH] Add separate preamble for listings without the color package

When generating changebars, or other markup not using color for showing
added/removed sections, the preamble for the listings package shall not
pull in the color package as that will lead to added listings to be
blue even though no color is expected in this mode.
---
 latexdiff | 22 +++++++++++++++++++++-
 1 file changed, 21 insertions(+), 1 deletion(-)

diff --git a/latexdiff b/latexdiff
index 5ff8a3c..67345f1 100755
--- a/latexdiff
+++ b/latexdiff
@@ -1096,6 +1096,9 @@ $ulem = ($latexdiffpreamble =~ /\\RequirePackage(?:\[$brat_n\])?\{ulem\}/ || def
 # If listings is being used or can be found in the latexdiff search path, add to the preamble auxiliary code to enable line-by-line markup
 if ( defined($packages{"listings"}) or `kpsewhich listings.sty` ne "" ) {
   my @listingpreamble=extrapream("LISTINGS");
+  if ($latexdiffpreamble =~ /\\RequirePackage(?:\[$brat_n\])?\{color\}/ ) {
+    @listingpreamble=extrapream("COLORLISTINGS");
+  }
   my @listingDIFcode=();
   my $replaced;
   # note that in case user supplies preamblefile the type might not reflect well the 
@@ -5484,7 +5487,6 @@ verbatim[*]?
 
 %DIF LISTINGS PREAMBLE
 \RequirePackage{listings}
-\RequirePackage{color}
 \lstdefinelanguage{DIFcode}{
   % note that the definitions in the following two lines are overwritten dependent on the markup type selected %DIFCODE TEMPLATE
   morecomment=[il]{\%DIF\ <\ },          %DIFCODE TEMPLATE
@@ -5500,6 +5502,24 @@ verbatim[*]?
 \lstnewenvironment{DIFverbatim*}{\lstset{style=DIFverbatimstyle,showspaces=true}}{}
 %DIF END LISTINGS PREAMBLE
 
+%DIF COLORLISTINGS PREAMBLE
+\RequirePackage{listings}
+\RequirePackage{color}
+\lstdefinelanguage{DIFcode}{
+  % note that the definitions in the following two lines are overwritten dependent on the markup type selected %DIFCODE TEMPLATE
+  morecomment=[il]{\%DIF\ <\ },          %DIFCODE TEMPLATE
+  moredelim=[il][\bfseries]{\%DIF\ >\ }  %DIFCODE TEMPLATE
+}
+\lstdefinestyle{DIFverbatimstyle}{
+	language=DIFcode,
+	basicstyle=\ttfamily,
+	columns=fullflexible,
+	keepspaces=true
+}
+\lstnewenvironment{DIFverbatim}{\lstset{style=DIFverbatimstyle}}{}
+\lstnewenvironment{DIFverbatim*}{\lstset{style=DIFverbatimstyle,showspaces=true}}{}
+%DIF END COLORLISTINGS PREAMBLE
+
 %DIF DIFCODE_UNDERLINE
   moredelim=[il][\color{red}\sout]{\%DIF\ <\ },
   moredelim=[il][\color{blue}\uwave]{\%DIF\ >\ }