package/zziplib: create symlinks only if target is missing

Symlink creation to base file names is only needed for versioned libraries.
Modify CMake rules to prevent overwriting existing libraties with recursive
links.

Fixes the following autobuild failures:
http://autobuild.buildroot.net/results/dd1/dd1974dbc1a22a96a3cedb117417e66119821514/
http://autobuild.buildroot.net/results/df8/df8406402ccff7cec34ae5858b8da57d1a4ae9c1/
http://autobuild.buildroot.net/results/743/7433a2ad111e2f014c81f196d3d1e2f63dffa858/
http://autobuild.buildroot.net/results/79f/79f88e9ec14cda7d07cf689eee864791ba949892/
...
http://autobuild.buildroot.net/results/892/8922efbbbfe79e8286a411acce4086b5c77c57c0/
http://autobuild.buildroot.net/results/dfa/dfa8ade3a4c1750e6dd58e652f60af2a44f80dd8/
http://autobuild.buildroot.net/results/9cd/9cd4147486f32d642513ba14efca3a02d5745ab9/

Regression test cases:
http://autobuild.buildroot.net/results/ba7/ba711034c0abe980f677e26de41739223e2f66e9/
http://autobuild.buildroot.net/results/032/032aaff121fb114f388c67dbca3ad2b02f670e38/
http://autobuild.buildroot.net/results/6c5/6c56b645a2b723920f07b98474452824fba5e2c1/

Signed-off-by: Andreas Ziegler <br015@umbiko.net>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
(cherry picked from commit 3e15fe6a5e91def9fce5b7d19b1f78c072bdab41)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/zziplib/0002-ZZIP_LIBLATEST-create-symlinks-only-if-target-is-mis.patch

@@ -0,0 +1,72 @@
+From 5977725ecea038f32a86938703ca1ed2b080b31c Mon Sep 17 00:00:00 2001
+From: Andreas Ziegler <br015@umbiko.net>
+Date: Fri, 29 Jul 2022 12:32:27 +0200
+Subject: [PATCH] ZZIP_LIBLATEST: create symlinks only if target is missing
+
+zzip/CMakeList.txt uses custom build targets to create symlinks to the
+(normally versioned) build results from unversioned file names. These
+targets are executed unconditionally, every time a build is started,
+regardless of the existence of the symlink.
+
+Debug builds, however, generate unversioned libraries. The build targets
+therefore overwrite existing files with recursive links.
+
+Create custom targets depending on the target file plus custom build
+commands containing the symlink creation, thereby ensuring that symlinks
+are only created if the link target is missing.
+
+Signed-off-by: Andreas Ziegler <br015@umbiko.net>
+Upstream: https://github.com/gdraheim/zziplib/pull/138
+---
+ zzip/CMakeLists.txt | 18 +++++++++++++++---
+ 1 file changed, 15 insertions(+), 3 deletions(-)
+
+diff --git a/zzip/CMakeLists.txt b/zzip/CMakeLists.txt
+index 4fa6b9c..dd1e56a 100644
+--- a/zzip/CMakeLists.txt
++++ b/zzip/CMakeLists.txt
+@@ -350,8 +350,12 @@ if(ZZIP_LIBLATEST)
+   endif()
+     get_target_property(libname libzzip OUTPUT_NAME)
+     get_target_property(librelease libzzip RELEASE_POSTFIX)
++    set(libzzip_target "${lib}${libname}${dll}")
++    add_custom_command(OUTPUT ${libzzip_target} 
++        COMMAND ${CMAKE_COMMAND} -E create_symlink $<TARGET_FILE_NAME:libzzip> ${libzzip_target}
++        )
+     add_custom_target(libzzip_latest ALL
+-        COMMAND ${CMAKE_COMMAND} -E create_symlink $<TARGET_FILE_NAME:libzzip> ${lib}${libname}${dll}
++        DEPENDS ${libzzip_target}
+         )
+     install(FILES
+         ${outdir}/${lib}${libname}${dll}
+@@ -359,8 +363,12 @@ if(ZZIP_LIBLATEST)
+     if(ZZIPFSEEKO)
+     get_target_property(libname libzzipfseeko OUTPUT_NAME)
+     get_target_property(librelease libzzipfseeko RELEASE_POSTFIX)
++    set(libzzipfseeko_target "${lib}${libname}${dll}")
++    add_custom_command(OUTPUT ${libzzipfseeko_target} 
++        COMMAND ${CMAKE_COMMAND} -E create_symlink $<TARGET_FILE_NAME:libzzipfseeko> ${libzzipfseeko_target}
++        )
+     add_custom_target(libzzipfseeko_latest ALL
+-        COMMAND ${CMAKE_COMMAND} -E create_symlink $<TARGET_FILE_NAME:libzzipfseeko> ${lib}${libname}${dll}
++        DEPENDS ${libzzipfseeko_target}
+         )
+     install(FILES
+         ${outdir}/${lib}${libname}${dll}
+@@ -369,8 +377,12 @@ if(ZZIP_LIBLATEST)
+     if(ZZIPMMAPPED)
+     get_target_property(libname libzzipmmapped OUTPUT_NAME)
+     get_target_property(librelease libzzipmmapped RELEASE_POSTFIX)
++    set(libzzipmmapped_target "${lib}${libname}${dll}")
++    add_custom_command(OUTPUT ${libzzipmmapped_target} 
++        COMMAND ${CMAKE_COMMAND} -E create_symlink $<TARGET_FILE_NAME:libzzipmmapped> ${libzzipmmapped_target}
++        )
+     add_custom_target(libzzipmmaped_latest ALL
+-        COMMAND ${CMAKE_COMMAND} -E create_symlink $<TARGET_FILE_NAME:libzzipmmapped> ${lib}${libname}${dll}
++        DEPENDS ${libzzipmmapped_target}
+         )
+     install(FILES
+         ${outdir}/${lib}${libname}${dll}
+-- 
+2.34.1
+