pcb parser: ensure the parser is reinitialized before parsing a new fp file

Because the same parser is used to read all footprint files of a library,
the parser must be reinitialized (internal variable cleared) before reading
a new file, otherwise the previous parser state is applied to the next file.
Fixes #7627
https://gitlab.com/kicad/code/kicad/issues/7627

common/dsnlexer.cpp

@@ -146,6 +146,7 @@ DSNLEXER::~DSNLEXER()
     }
 }
 
+
 void DSNLEXER::SetSpecctraMode( bool aMode )
 {
     specctraMode = aMode;
@@ -162,6 +163,16 @@ void DSNLEXER::SetSpecctraMode( bool aMode )
 }
 
 
+void DSNLEXER::InitParserState()
+{
+    curTok  = DSN_NONE;
+    prevTok = DSN_NONE;
+    commentsAreTokens = false;
+
+    curOffset = 0;
+}
+
+
 bool DSNLEXER::SyncLineReaderWith( DSNLEXER& aLexer )
 {
     // Synchronize the pointers handling the data read by the LINE_READER

include/dsnlexer.h

@@ -131,6 +131,13 @@ public:
 
     virtual ~DSNLEXER();
 
+    /**
+     * Reinit variables used during parsing, to ensure od states are not used in a new parsing
+     * must be called before parsing a new file after parsing an old file to avoid
+     * starting with some variables in a non initial state
+     */
+    void InitParserState();
+
     /**
      * Usable only for DSN lexers which share the same #LINE_READER.
      *

pcbnew/plugins/kicad/kicad_plugin.cpp

@@ -265,6 +265,8 @@ void FP_CACHE::Load()
                 FILE_LINE_READER    reader( fn.GetFullPath() );
 
                 m_owner->m_parser->SetLineReader( &reader );
+                // Ensure a previous parsing does not interacts with the new parsing:
+                m_owner->m_parser->InitParserState();
 
                 FOOTPRINT* footprint = (FOOTPRINT*) m_owner->m_parser->Parse();
                 wxString   fpName = fn.GetName();

pcbnew/plugins/kicad/pcb_parser.cpp

@@ -637,6 +637,9 @@ BOARD_ITEM* PCB_PARSER::Parse()
 
     token = CurTok();
 
+    if( token == -1 )   // EOF
+        Unexpected( token );
+
     if( token != T_LEFT )
         Expecting( T_LEFT );