CPack: Fix regression in Deb description

Fixes: #20254

6 files changed, 20 insertions, 9 deletions

diff --git a/Modules/CPack.cmake b/Modules/CPack.cmake
index a1cc71d..c2ed3de 100644
--- a/Modules/CPack.cmake
+++ b/Modules/CPack.cmake
@@ -458,12 +458,13 @@ if(NOT DEFINED CPACK_PACKAGE_VERSION)
 endif()
 
 _cpack_set_default(CPACK_PACKAGE_VENDOR "Humanity")
+set(CPACK_DEFAULT_PACKAGE_DESCRIPTION_SUMMARY "${CMAKE_PROJECT_NAME} built using CMake")
 if(CMAKE_PROJECT_DESCRIPTION)
   _cpack_set_default(CPACK_PACKAGE_DESCRIPTION_SUMMARY
     "${CMAKE_PROJECT_DESCRIPTION}")
 else()
   _cpack_set_default(CPACK_PACKAGE_DESCRIPTION_SUMMARY
-    "${CMAKE_PROJECT_NAME} built using CMake")
+    "${CPACK_DEFAULT_PACKAGE_DESCRIPTION_SUMMARY}")
 endif()
 if(CMAKE_PROJECT_HOMEPAGE_URL)
   _cpack_set_default(CPACK_PACKAGE_HOMEPAGE_URL
diff --git a/Modules/Internal/CPack/CPackDeb.cmake b/Modules/Internal/CPack/CPackDeb.cmake
index 3927b1a..97906ca 100644
--- a/Modules/Internal/CPack/CPackDeb.cmake
+++ b/Modules/Internal/CPack/CPackDeb.cmake
@@ -540,7 +540,8 @@ function(cpack_deb_prepare_package_vars)
   # Ok, description has set. According to the `Debian Policy Manual`_ the frist
   # line is a pacakge summary.  Try to get it as well...
   # See also: https://www.debian.org/doc/debian-policy/ch-controlfields.html#description
-  elseif(CPACK_PACKAGE_DESCRIPTION_SUMMARY)
+  elseif(CPACK_PACKAGE_DESCRIPTION_SUMMARY AND
+         NOT CPACK_PACKAGE_DESCRIPTION_SUMMARY STREQUAL CPACK_DEFAULT_PACKAGE_DESCRIPTION_SUMMARY)
     # Merge summary w/ the detailed description
     string(PREPEND CPACK_DEBIAN_PACKAGE_DESCRIPTION "${CPACK_PACKAGE_DESCRIPTION_SUMMARY}\n")
   endif()
diff --git a/Tests/RunCMake/CPack/RunCMakeTest.cmake b/Tests/RunCMake/CPack/RunCMakeTest.cmake
index 745bc8a..c2382b0 100644
--- a/Tests/RunCMake/CPack/RunCMakeTest.cmake
+++ b/Tests/RunCMake/CPack/RunCMakeTest.cmake
@@ -38,7 +38,7 @@ run_cpack_test(DEB_PACKAGE_VERSION_BACK_COMPATIBILITY "DEB.DEB_PACKAGE_VERSION_B
 run_cpack_test_subtests(EXTERNAL "none;good;good_multi;bad_major;bad_minor;invalid_good;invalid_bad;stage_and_package" "External" false "MONOLITHIC;COMPONENT")
 run_cpack_test_subtests(
   DEB_DESCRIPTION
-  "CPACK_DEBIAN_PACKAGE_DESCRIPTION;CPACK_PACKAGE_DESCRIPTION;CPACK_PACKAGE_DESCRIPTION_FILE;CPACK_NO_PACKAGE_DESCRIPTION"
+  "CPACK_DEBIAN_PACKAGE_DESCRIPTION;CPACK_PACKAGE_DESCRIPTION;CPACK_COMPONENT_COMP_DESCRIPTION;CPACK_PACKAGE_DESCRIPTION_FILE;CPACK_NO_PACKAGE_DESCRIPTION"
   "DEB.DEB_DESCRIPTION"
   false
   "MONOLITHIC;COMPONENT"
diff --git a/Tests/RunCMake/CPack/tests/DEB_DESCRIPTION/VerifyResult.cmake b/Tests/RunCMake/CPack/tests/DEB_DESCRIPTION/VerifyResult.cmake
index a8e2e7a..bfe2059 100644
--- a/Tests/RunCMake/CPack/tests/DEB_DESCRIPTION/VerifyResult.cmake
+++ b/Tests/RunCMake/CPack/tests/DEB_DESCRIPTION/VerifyResult.cmake
@@ -58,6 +58,8 @@ if(RunCMake_SUBTEST_SUFFIX STREQUAL "CPACK_PACKAGE_DESCRIPTION_FILE" AND PACKAGI
   string(APPEND _expected_description "\n  ." )
 elseif(RunCMake_SUBTEST_SUFFIX STREQUAL "CPACK_NO_PACKAGE_DESCRIPTION")
   set(_expected_description [[ Description: This is the summary line]])
+elseif(RunCMake_SUBTEST_SUFFIX STREQUAL "CPACK_COMPONENT_COMP_DESCRIPTION")
+  set(_expected_description [[ Description: One line description]])
 endif()
 
 foreach(_file_no RANGE 1 ${EXPECTED_FILES_COUNT})
diff --git a/Tests/RunCMake/CPack/tests/DEB_DESCRIPTION/test.cmake b/Tests/RunCMake/CPack/tests/DEB_DESCRIPTION/test.cmake
index ce3f651..893eb01 100644
--- a/Tests/RunCMake/CPack/tests/DEB_DESCRIPTION/test.cmake
+++ b/Tests/RunCMake/CPack/tests/DEB_DESCRIPTION/test.cmake
@@ -34,6 +34,16 @@ elseif(RunCMake_SUBTEST_SUFFIX STREQUAL "CPACK_PACKAGE_DESCRIPTION")
     set(CPACK_PACKAGE_DESCRIPTION "${_description}")
   endif()
 
+elseif(RunCMake_SUBTEST_SUFFIX STREQUAL "CPACK_COMPONENT_COMP_DESCRIPTION")
+  # NOTE Documented fallback variable without CPACK_PACKAGE_DESCRIPTION_SUMMARY
+  if(PACKAGING_TYPE STREQUAL "COMPONENT")
+    set(CPACK_COMPONENT_SATU_DESCRIPTION "One line description")
+    set(CPACK_COMPONENT_DUA_DESCRIPTION "One line description")
+  else()
+    set(CPACK_PACKAGE_DESCRIPTION "One line description")
+  endif()
+  unset(CPACK_PACKAGE_DESCRIPTION_SUMMARY)
+
 elseif(RunCMake_SUBTEST_SUFFIX STREQUAL "CPACK_PACKAGE_DESCRIPTION_FILE")
   # NOTE Getting the description from the file
   set(_file "${CMAKE_CURRENT_BINARY_DIR}/description.txt")
diff --git a/Tests/RunCMake/CPack/tests/PER_COMPONENT_FIELDS/VerifyResult.cmake b/Tests/RunCMake/CPack/tests/PER_COMPONENT_FIELDS/VerifyResult.cmake
index c47b40e..b4bdb61 100644
--- a/Tests/RunCMake/CPack/tests/PER_COMPONENT_FIELDS/VerifyResult.cmake
+++ b/Tests/RunCMake/CPack/tests/PER_COMPONENT_FIELDS/VerifyResult.cmake
@@ -8,9 +8,6 @@ endfunction()
 if(GENERATOR_TYPE STREQUAL "DEB")
   set(name_ "Package")
   set(group_ "Section")
-  # NOTE For a Debian package the first line of the `Description`
-  # field is generated by CMake and gonna be ignored
-  set(ignore_rest_cond_ ".*\n")
 elseif(GENERATOR_TYPE STREQUAL "RPM")
   set(name_ "Name")
   set(group_ "Group")
@@ -36,6 +33,6 @@ if(GENERATOR_TYPE STREQUAL "RPM")
 endif()
 
 # check package description
-checkPackageInfo_("description" "${FOUND_FILE_1}" ".*Description${whitespaces_}:${ignore_rest_cond_}${whitespaces_}Description for pkg_1")
-checkPackageInfo_("description" "${FOUND_FILE_2}" ".*Description${whitespaces_}:${ignore_rest_cond_}${whitespaces_}Description for pkg_2")
-checkPackageInfo_("description" "${FOUND_FILE_3}" ".*Description${whitespaces_}:${ignore_rest_cond_}${whitespaces_}Description for pkg_3")
+checkPackageInfo_("description" "${FOUND_FILE_1}" ".*Description${whitespaces_}:${whitespaces_}Description for pkg_1")
+checkPackageInfo_("description" "${FOUND_FILE_2}" ".*Description${whitespaces_}:${whitespaces_}Description for pkg_2")
+checkPackageInfo_("description" "${FOUND_FILE_3}" ".*Description${whitespaces_}:${whitespaces_}Description for pkg_3")