File reproducible.patch of Package libcec

https://github.com/Pulse-Eight/libcec/pull/553

commit 8e97b159b28ce4b21d183ff68983b5b727fa2c1b
Author: Bernhard M. Wiedemann <bwiedemann@suse.de>
Date:   Sat Jan 16 22:50:02 2021 +0100

    Allow to skip recording build user+host
    
    if the SOURCE_DATE_EPOCH variable is set,
    this indicates that a reproducible build is wanted.
    
    This PR was done while working on reproducible builds for openSUSE.

diff --git a/src/libcec/cmake/SetBuildInfo.cmake b/src/libcec/cmake/SetBuildInfo.cmake
index 3402f9f..29e4e70 100644
--- a/src/libcec/cmake/SetBuildInfo.cmake
+++ b/src/libcec/cmake/SetBuildInfo.cmake
@@ -31,6 +31,9 @@ else()
   find_program(HAVE_WHOAMI_BIN whoami /bin /usr/bin /usr/local/bin)
   if(HAVE_WHOAMI_BIN)
     exec_program(whoami OUTPUT_VARIABLE BUILD_USER)
+    if (DEFINED ENV{SOURCE_DATE_EPOCH})
+      set(BUILD_USER "(reproducible)")
+    endif()
     set(LIB_INFO "${LIB_INFO} by ${BUILD_USER}")
   else()
     set(LIB_INFO "${LIB_INFO} by (unknown user)")
@@ -44,6 +47,9 @@ else()
     if (RETURN_HOST)
       exec_program(hostname OUTPUT_VARIABLE BUILD_HOST)
     endif()
+    if (DEFINED ENV{SOURCE_DATE_EPOCH})
+      set(BUILD_HOST "(reproducible)")
+    endif()
     set(LIB_INFO "${LIB_INFO}@${BUILD_HOST}")
   endif()