Fix problem with biblatex textcite command

latexdiff

@@ -32,6 +32,7 @@
 ###  - change meaning of --packages option such that this packages are used in addition of automatically detected packages (possibly introduce option --only-packages that overrides automatic choices completely
 # Version 1.3.2
 #  - extend CUSTOMDIFCMD related postprocessing to deal properly with multiline commands, or a sequence of several commands in the same line (see github issue #204)
+#  - fix a bug in biblatex mode, which prevented proper processing of modified \textcite (see: https://tex.stackexchange.com/questions/555157/latexdiff-and-biblatex-citation-commands)
 #
 # Version 1.3.1.1
 #  - remove spurious \n to fix error: Unknown regexp modifier "/n" at .../latexdiff line 1974, near "=~ " (see github issue #201)
@@ -1263,6 +1264,7 @@ if ( defined $packages{"apacite"}  ) {
 } elsif (defined $packages{"biblatex"}) {
   print STDERR "biblatex package detected.\n" if $verbose ;
   $citpat='(?:[cC]ites?|(?:[pP]aren|foot|[Tt]ext|[sS]mart|super)cites?\*?|footnotecitetex)';
+  push(@TEXTCMDEXCL, qr/^textcite$/);
 } else {
   # citation command pattern for all other citation schemes
 ###  $citpatsafe=qr/^cite.*$/;

testsuite/biblatex-new.tex

@@ -0,0 +1,30 @@
+\documentclass[a4paper]{article}
+\usepackage[utf8]{inputenc}
+\usepackage{filecontents}
+\begin{filecontents}{bibliography.bib}
+@article{greenwade93,
+    author  = "George D. Greenwade",
+    title   = "The {C}omprehensive {T}ex {A}rchive {N}etwork ({CTAN})",
+    year    = "1993",
+    journal = "TUGBoat",
+    volume  = "14",
+    number  = "3",
+    pages   = "342--351"
+}
+@book{goossens93,
+    author    = "Michel Goossens and Frank Mittelbach and Alexander Samarin",
+    title     = "The LaTeX Companion",
+    year      = "1993",
+    publisher = "Addison-Wesley",
+    address   = "Reading, Massachusetts"
+}
+\end{filecontents}
+\usepackage[style=apa,backend=biber]{biblatex}
+\addbibresource{bibliography.bib}
+\begin{document}
+
+\textcite{goossens93} is the best book on \LaTeX \parencite{greenwade93}.
+
+\printbibliography
+
+\end{document}

testsuite/biblatex-old.tex

@@ -0,0 +1,31 @@
+\documentclass[a4paper]{article}
+\usepackage[utf8]{inputenc}
+\usepackage{filecontents}
+\begin{filecontents}{bibliography.bib}
+@article{greenwade93,
+    author  = "George D. Greenwade",
+    title   = "The {C}omprehensive {T}ex {A}rchive {N}etwork ({CTAN})",
+    year    = "1993",
+    journal = "TUGBoat",
+    volume  = "14",
+    number  = "3",
+    pages   = "342--351"
+}
+@book{goossens93,
+    author    = "Michel Goossens and Frank Mittelbach and Alexander Samarin",
+    title     = "The LaTeX Companion",
+    year      = "1993",
+    publisher = "Addison-Wesley",
+    address   = "Reading, Massachusetts"
+}
+\end{filecontents}
+\usepackage[style=apa,backend=biber]{biblatex}
+\addbibresource{bibliography.bib}
+\begin{document}
+
+\textcite{greenwade93} is the best article on \LaTeX \parencite{goossens93}.
+
+\printbibliography
+
+\end{document}
+

testsuite/verify

@@ -21,7 +21,7 @@ delequ latin9 pollack move-equation nomarkup subscript doubledollar intertext \
 DIFDELCMDBUG eqnarray eqnarray2 subscriptm delequ2 schneider gennady umesh underwood endfloat endfloat2 outerrise \
 delequ3 delequ4 "simplefrac --allow-spaces" "master --flatten" "subfile --flatten" titlediffTest2 exampleDiff bornd2 \
 "rolla --math-markup=2" mini "complex-maths --math-markup=1" margalit circonflex mwe-comment "apacite-test --flatten" quoteddollarunderscore units complicated-math move-equation2 lists "figures --graphics-markup=both" alignat "safecmd --append-safecmd=remark" verbatim verbatim2-is143 embedded-math-array "verbatim-input --flatten" anchordemo 'customdiffcmdtest --add-to-config "CUSTOMDIFCMD=blindtext;mypar;donothing;cmd"' description frac_w_space_comments \
-"href-in-bibliography --append-safecmd=path" revtex-bibliography \
+"href-in-bibliography --append-safecmd=path" revtex-bibliography biblatex \
 )
 
 #set testroots= ( test subscript )