diff --git a/thunderbird-115.5.0-icu-74.1.patch b/thunderbird-115.5.0-icu-74.1.patch
new file mode 100644
index 0000000..617dd76
--- /dev/null
+++ b/thunderbird-115.5.0-icu-74.1.patch
@@ -0,0 +1,41 @@
+https://bugs.gentoo.org/917599
+https://bugzilla.mozilla.org/show_bug.cgi?id=1862601
+https://hg.mozilla.org/try/rev/d5f3b0c4f08a426ce00a153c04e177eecb6820e2
+
+# HG changeset patch
+# User André Bargull <andre.bargull@gmail.com>
+# Date 1697435923 -7200
+# Node ID d5f3b0c4f08a426ce00a153c04e177eecb6820e2
+# Parent  c63994f8259efdf6e745c960aa9e1409d5477049
+Bug xxx - Part 12: Add new line break classes. r?
+
+diff --git a/intl/lwbrk/LineBreaker.cpp b/intl/lwbrk/LineBreaker.cpp
+--- a/intl/lwbrk/LineBreaker.cpp
++++ b/intl/lwbrk/LineBreaker.cpp
+@@ -443,17 +443,23 @@ static int8_t GetClass(uint32_t u, LineB
+       /* JT = 34,                           [JT] */ CLASS_CHARACTER,
+       /* JV = 35,                           [JV] */ CLASS_CHARACTER,
+       /* CLOSE_PARENTHESIS = 36,            [CP] */ CLASS_CLOSE_LIKE_CHARACTER,
+       /* CONDITIONAL_JAPANESE_STARTER = 37, [CJ] */ CLASS_CLOSE,
+       /* HEBREW_LETTER = 38,                [HL] */ CLASS_CHARACTER,
+       /* REGIONAL_INDICATOR = 39,           [RI] */ CLASS_CHARACTER,
+       /* E_BASE = 40,                       [EB] */ CLASS_BREAKABLE,
+       /* E_MODIFIER = 41,                   [EM] */ CLASS_CHARACTER,
+-      /* ZWJ = 42,                          [ZWJ]*/ CLASS_CHARACTER};
++      /* ZWJ = 42,                          [ZWJ]*/ CLASS_CHARACTER,
++      /* AKSARA = 43,                       [AK] */ CLASS_CHARACTER,
++      /* AKSARA_PREBASE = 44,               [AP] */ CLASS_CHARACTER,
++      /* AKSARA_START = 45,                 [AS] */ CLASS_CHARACTER,
++      /* VIRAMA_FINAL = 46,                 [VF] */ CLASS_CHARACTER,
++      /* VIRAMA = 47,                       [VI] */ CLASS_CHARACTER,
++  };
+ 
+   static_assert(U_LB_COUNT == mozilla::ArrayLength(sUnicodeLineBreakToClass),
+                 "Gecko vs ICU LineBreak class mismatch");
+ 
+   auto cls = GetLineBreakClass(u);
+   MOZ_ASSERT(cls < mozilla::ArrayLength(sUnicodeLineBreakToClass));
+ 
+   // Overrides based on rules for the different line-break values given in
+
+
diff --git a/thunderbird.spec b/thunderbird.spec
index 4b31926..f8878ef 100644
--- a/thunderbird.spec
+++ b/thunderbird.spec
@@ -8,7 +8,7 @@
 #%define        source_dir                  comm-esr%(echo %version | cut -d. -f1)
 
 Name:          thunderbird
-Version:       115.4.1
+Version:       115.5.0
 Release:       1mamba
 Summary:       Mozilla Thunderbird email, RSS, and newsgroup client
 Group:         Graphical Desktop/Applications/Internet
@@ -28,6 +28,7 @@ Patch15:       thunderbird-78.8.1-fix-passing-system-bzip2-ldflags.patch
 Patch16:       thunderbird-91.4.1-python-setuptools-60.0.4.patch
 Patch17:       thunderbird-91.5.1-libwayland-1.20.0.patch
 Patch18:       thunderbird-102.3.2-cbindgen-0.24.patch
+Patch19:       thunderbird-115.5.0-icu-74.1.patch
 License:       GPL,MPL 1.1,LGPL
 ## AUTOBUILDREQ-BEGIN
 BuildRequires: firefox-devel
@@ -204,7 +205,7 @@ This package contains the %{2} language support files for Thunderbird.\
 #% debug_package
 
 %prep
-%setup -q -c
+%setup -q
 #-D -T
 #:<< ___EOF
 
@@ -214,10 +215,9 @@ This package contains the %{2} language support files for Thunderbird.\
 %global __provides_exclude_from ^%{_libdir}/thunderbird/.*$
 %global __requires_exclude ^(libxul\\.so.*|libldap.*\\.so.*|libldif.*\\.so.*|libmoz.*\\.so.*|libprldap.*\\.so.*|librnp\\.so.*)$
 
-cd thunderbird-%{version}
-
 #%patch16 -p1
 #%patch18 -p1 -b .cbindgen-0.24
+%patch 19 -p1 -b .icu-74.1
 
 rm -f .mozconfig
 cat << EOF > .mozconfig
@@ -286,8 +286,6 @@ EOF
 
 %build
 #:<< ___EOF
-cd thunderbird-%{version}
-
 export PYTHON=%{__python3}
 
 # Pass libstdc++ headers dirs to clang 
@@ -308,8 +306,6 @@ export MACH_BUILD_PYTHON_NATIVE_PACKAGE_SOURCE=none
 
 %install
 [ "%{buildroot}" != / ] && rm -rf "%{buildroot}"
-cd thunderbird-%{version}
-
 export DESTDIR=%{buildroot}
 ./mach install
 
@@ -433,6 +429,9 @@ fi
 %exclude %{_libdir}/thunderbird/distribution/extensions/langpack-*@thunderbird.mozilla.org.xpi
 
 %changelog
+* Sat Nov 25 2023 Automatic Build System <autodist@mambasoft.it> 115.5.0-1mamba
+- automatic version update by autodist
+
 * Thu Oct 26 2023 Automatic Build System <autodist@mambasoft.it> 115.4.1-1mamba
 - automatic version update by autodist