Guess running kernel from testcase if --uname is not provided

tools/zypp-runpurge.cc

@@ -34,7 +34,7 @@ int main ( int argc, char *argv[] )
 
   auto result = options.parse( argc, argv );
 
-  if ( result.count( "help" ) || !result.count("uname") || !result.positionals().size() )
+  if ( result.count( "help" ) || !result.positionals().size() )
     return usage( options, 1 );
 
   const std::string &testcaseDir = result.positionals().front();
@@ -58,24 +58,48 @@ int main ( int argc, char *argv[] )
     return 1;
   }
 
+  std::string unameR;
+  if ( result.count("uname") ) {
+    unameR = result["uname"].arg();
+  } else {
+    std::cout << "No --uname provided. Guessing it from the latest kernel-default installed...." << std::endl;
+    const PoolItem & running( ui::Selectable::get("kernel-default")->theObj() );
+    if ( not running ) {
+      std::cerr << "Oops: No installed kernel-default." << std::endl;
+      return usage( options, 1 );
+    }
+    std::cout << "Guess running: " << running.asString() << endl;
+    const Capability unameRProvides { "kernel-uname-r" }; // indicator provides
+    for ( const auto & cap : running.provides() ) {
+      if ( cap.matches( unameRProvides ) == CapMatch::yes ) {
+        unameR = cap.detail().ed().asString();
+        break;
+      }
+    }
+    if ( unameR.empty() ) {
+      std::cerr << "Oops: Guessed kernel does not provide " << unameRProvides << std::endl;
+      return usage( options, 1 );
+    }
+    std::cout << "Guess --uname: " << unameR << endl;
+  }
+
   std::string keepSpec = "oldest,running,latest";
   if ( result.count("keepSpec") ) {
     keepSpec = result["keepSpec"].arg();
   }
 
+
   PurgeKernels krnls;
-  krnls.setUnameR( result["uname"].arg() );
+  krnls.setUnameR( unameR );
   krnls.setKeepSpec( keepSpec );
   krnls.markObsoleteKernels();
 
-  const auto &makeNVRA = []( const PoolItem &pck ) -> std::string  {
-    return pck.name() + "-" + pck.edition().asString() + "." + pck.arch().asString();
-  };
 
+  std::cout << "Purged kernels: " << std::endl;
   auto pool = ResPool::instance();
   const filter::ByStatus toBeUninstalledFilter( &ResStatus::isToBeUninstalled );
   for ( auto it = pool.byStatusBegin( toBeUninstalledFilter ); it != pool.byStatusEnd( toBeUninstalledFilter );  it++  ) {
-    std::cout << "Removing " << makeNVRA(*it) + (it->status().isByUser() ? " (by user)" : " (autoremoved)") << std::endl;
+    std::cout << "Removing " << it->asString() + (it->status().isByUser() ? " (by user)" : " (autoremoved)") << std::endl;
   }
 
   return 0;