Revert absolute-path asserts and fix off-by-one bug.

Fixes: lp:1767582
* https://bugs.launchpad.net/kicad/+bug/1767582

common/project.cpp

@@ -78,9 +78,7 @@ void PROJECT::SetProjectFullName( const wxString& aFullPathAndName )
 
         m_project_name = aFullPathAndName;
 
-        // There's no guarantee that this path is absolute.  For instance, a relative
-        // path might have been passed via the command line.
-        // wxASSERT( m_project_name.IsAbsolute() );
+        wxASSERT( m_project_name.IsAbsolute() );
 
         wxASSERT( m_project_name.GetExt() == ProjectFileExtension );
 

common/single_top.cpp

@@ -365,11 +365,11 @@ bool PGM_SINGLE_TOP::OnPgmInit()
             argSet.push_back( App().argv[i] );
         }
 
-        // special attention to the first argument: argv[1] (==argSet[0])
-        wxFileName argv1( argSet[0] );
-
-        if( argc - args_offset > 1 )
+        // special attention to a single argument: argv[1] (==argSet[0])
+        if( argc == args_offset + 1 )
         {
+            wxFileName argv1( argSet[0] );
+
 #if defined(PGM_DATA_FILE_EXT)
             // PGM_DATA_FILE_EXT, if present, may be different for each compile,
             // it may come from CMake on the compiler command line, but often does not.

eeschema/files-io.cpp

@@ -201,6 +201,9 @@ bool SCH_EDIT_FRAME::OpenProjectFiles( const std::vector<wxString>& aFileSet, in
 
     wxString    fullFileName( aFileSet[0] );
 
+    // We insist on caller sending us an absolute path, if it does not, we say it's a bug.
+    wxASSERT_MSG( wxFileName( fullFileName ).IsAbsolute(), wxT( "Path is not absolute!" ) );
+
     if( !LockFile( fullFileName ) )
     {
         wxString msg = wxString::Format( _( "Schematic file \"%s\" is already open." ),