Be more robust around filesystems that don't support timestamps (KICAD-R7V).

(cherry picked from commit 6b32815887)

eeschema/sch_io/altium/sch_io_altium.cpp

@@ -4774,7 +4774,7 @@ long long SCH_IO_ALTIUM::getLibraryTimestamp( const wxString& aLibraryPath ) con
     if( fn.IsFileReadable() && fn.GetModificationTime().IsValid() )
         return fn.GetModificationTime().GetValue().GetValue();
     else
-        return wxDateTime( 0.0 ).GetValue().GetValue();
+        return 0;
 }
 
 

eeschema/sch_io/cadstar/sch_io_cadstar_archive.cpp

@@ -298,10 +298,9 @@ void SCH_IO_CADSTAR_ARCHIVE::ensureLoadedLibrary( const wxString& aLibraryPath,
     long long  timestamp = 0;
     wxFileName fn( aLibraryPath );
 
-    if( fn.IsFileReadable() )
+    if( fn.IsFileReadable() && fn.GetModificationTime().IsValid() )
         timestamp = fn.GetModificationTime().GetValue().GetValue();
 
-
     if( fn.IsFileReadable()
         && m_cachePath == aLibraryPath
         && m_cachecsafn.GetFullPath() == csafn.GetFullPath()

eeschema/sch_io/eagle/sch_io_eagle.cpp

@@ -542,7 +542,7 @@ long long SCH_IO_EAGLE::getLibraryTimestamp( const wxString& aLibraryPath ) cons
     if( fn.IsFileReadable() && fn.GetModificationTime().IsValid() )
         return fn.GetModificationTime().GetValue().GetValue();
     else
-        return wxDateTime( 0.0 ).GetValue().GetValue();
+        return 0;
 }
 
 

eeschema/sch_io/kicad_legacy/sch_io_kicad_legacy.cpp

@@ -2250,7 +2250,7 @@ void SCH_IO_KICAD_LEGACY::CreateLibrary( const wxString& aLibraryPath,
     m_cache = new SCH_IO_KICAD_LEGACY_LIB_CACHE( aLibraryPath );
     m_cache->SetModified();
     m_cache->Save( writeDocFile( aProperties ) );
-    m_cache->Load();    // update m_writable and m_mod_time
+    m_cache->Load();    // update m_writable and m_timestamp
 }
 
 

eeschema/sch_io/kicad_sexpr/sch_io_kicad_sexpr.cpp

@@ -1662,7 +1662,7 @@ void SCH_IO_KICAD_SEXPR::CreateLibrary( const wxString& aLibraryPath,
     m_cache = new SCH_IO_KICAD_SEXPR_LIB_CACHE( aLibraryPath );
     m_cache->SetModified();
     m_cache->Save();
-    m_cache->Load();    // update m_writable and m_mod_time
+    m_cache->Load();    // update m_writable and m_timestamp
 }
 
 

pcbnew/pcb_io/altium/pcb_io_altium_designer.cpp

@@ -157,20 +157,14 @@ long long PCB_IO_ALTIUM_DESIGNER::GetLibraryTimestamp( const wxString& aLibraryP
 {
     // File hasn't been loaded yet.
     if( aLibraryPath.IsEmpty() )
-    {
         return 0;
-    }
 
     wxFileName fn( aLibraryPath );
 
     if( fn.IsFileReadable() && fn.GetModificationTime().IsValid() )
-    {
         return fn.GetModificationTime().GetValue().GetValue();
-    }
     else
-    {
         return 0;
-    }
 }
 
 

pcbnew/pcb_io/eagle/pcb_io_eagle.cpp

@@ -230,7 +230,7 @@ PCB_IO_EAGLE::PCB_IO_EAGLE() :
         m_doneCount( 0 ),
         m_lastProgressCount( 0 ),
         m_totalCount( 0 ),
-        m_mod_time( wxDateTime::Now() )
+        m_timestamp( wxDateTime::Now().GetValue().GetValue() )
 {
     using namespace std::placeholders;
 
@@ -3173,18 +3173,18 @@ void PCB_IO_EAGLE::centerBoard()
 }
 
 
-wxDateTime PCB_IO_EAGLE::getModificationTime( const wxString& aPath )
+long long PCB_IO_EAGLE::GetLibraryTimestamp( const wxString& aPath ) const
 {
     // File hasn't been loaded yet.
     if( aPath.IsEmpty() )
-        return wxDateTime::Now();
+        return wxDateTime::Now().GetValue().GetValue();
 
     wxFileName  fn( aPath );
 
-    if( fn.IsFileReadable() )
-        return fn.GetModificationTime();
+    if( fn.IsFileReadable() && fn.GetModificationTime().IsValid() )
+        return fn.GetModificationTime().GetValue().GetValue();
     else
-        return wxDateTime( 0.0 );
+        return 0;
 }
 
 
@@ -3194,14 +3194,9 @@ void PCB_IO_EAGLE::cacheLib( const wxString& aLibPath )
 
     try
     {
-        wxDateTime  modtime = getModificationTime( aLibPath );
+        long long timestamp = GetLibraryTimestamp( aLibPath );
 
-        // Fixes assertions in wxWidgets debug builds for the wxDateTime object.  Refresh the
-        // cache if either of the wxDateTime objects are invalid or the last file modification
-        // time differs from the current file modification time.
-        bool load = !m_mod_time.IsValid() || !modtime.IsValid() || m_mod_time != modtime;
-
-        if( aLibPath != m_lib_path || load )
+        if( aLibPath != m_lib_path || m_timestamp != timestamp )
         {
             wxXmlNode*  doc;
             LOCALE_IO   toggle;     // toggles on, then off, the C locale.
@@ -3249,10 +3244,12 @@ void PCB_IO_EAGLE::cacheLib( const wxString& aLibPath )
             loadLibrary( library, nullptr );
             m_xpath->pop();
 
-            m_mod_time = modtime;
+            m_timestamp = timestamp;
         }
     }
-    catch(...){}
+    catch(...)
+    {
+    }
     // TODO: Handle exceptions
     // catch( file_parser_error fpe )
     // {

pcbnew/pcb_io/eagle/pcb_io_eagle.h

@@ -158,10 +158,7 @@ public:
                               bool  aKeepUUID = false,
                               const std::map<std::string, UTF8>* aProperties = nullptr ) override;
 
-    long long GetLibraryTimestamp( const wxString& aLibraryPath ) const override
-    {
-        return getModificationTime( aLibraryPath ).GetValue().GetValue();
-    }
+    long long GetLibraryTimestamp( const wxString& aLibraryPath ) const override;
 
     bool IsLibraryWritable( const wxString& aLibraryPath ) override
     {
@@ -355,13 +352,13 @@ private:
     unsigned            m_lastProgressCount;
     unsigned            m_totalCount;         ///< for progress reporting
 
-    int         m_min_trace;        ///< smallest trace we find on Load(), in BIU.
-    int         m_min_hole;         ///< smallest diameter hole we find on Load(), in BIU.
-    int         m_min_via;          ///< smallest via we find on Load(), in BIU.
-    int         m_min_annulus;      ///< smallest via annulus we find on Load(), in BIU.
+    int                 m_min_trace;        ///< smallest trace we find on Load(), in BIU.
+    int                 m_min_hole;         ///< smallest diameter hole we find on Load(), in BIU.
+    int                 m_min_via;          ///< smallest via we find on Load(), in BIU.
+    int                 m_min_annulus;      ///< smallest via annulus we find on Load(), in BIU.
 
-    wxString    m_lib_path;
-    wxDateTime  m_mod_time;
+    wxString            m_lib_path;
+    long long           m_timestamp;
 };
 
 #endif  // PCB_IO_EAGLE_H_

pcbnew/pcb_io/kicad_legacy/pcb_io_kicad_legacy.cpp

@@ -3015,7 +3015,12 @@ bool LP_CACHE::IsModified()
 
 long long LP_CACHE::GetTimestamp( const wxString& aLibPath )
 {
-    return wxFileName( aLibPath ).GetModificationTime().GetValue().GetValue();
+    wxFileName fn( aLibPath );
+
+    if( fn.IsFileReadable() && fn.GetModificationTime().IsValid() )
+        return fn.GetModificationTime().GetValue().GetValue();
+    else
+        return 0;
 }
 
 

pcbnew/pcb_io/kicad_sexpr/pcb_io_kicad_sexpr.cpp

@@ -162,7 +162,8 @@ void FP_CACHE::Save( FOOTPRINT* aFootprintFilter )
         m_cache_timestamp += fn.GetTimestamp();
     }
 
-    m_cache_timestamp += m_lib_path.GetModificationTime().GetValue().GetValue();
+    if( m_lib_path.IsFileReadable() && m_lib_path.GetModificationTime().IsValid() )
+        m_cache_timestamp += m_lib_path.GetModificationTime().GetValue().GetValue();
 
     // If we've saved the full cache, we clear the dirty flag.
     if( !aFootprintFilter )