CHANGED: Backup project only when different

Makes a test backup file and compares to the existing zip file backup to
see if the files have changed since it was made.  If so, the new file is
kept.  If not, we discard the new file and continue

Fixes https://gitlab.com/kicad/code/kicad/-/issues/12453

common/project/project_archiver.cpp

@@ -33,14 +33,47 @@
 #include <wxstream_helper.h>
 #include <wx/log.h>
 
+#include <set>
+
 
 #define ZipFileExtension wxT( "zip" )
 
-
 PROJECT_ARCHIVER::PROJECT_ARCHIVER()
 {
 }
 
+bool PROJECT_ARCHIVER::AreZipArchivesIdentical( const wxString& aZipFileA,
+                                                const wxString& aZipFileB, REPORTER& aReporter )
+{
+    wxFFileInputStream streamA( aZipFileA );
+    wxFFileInputStream streamB( aZipFileB );
+
+    if( !streamA.IsOk() || !streamB.IsOk() )
+    {
+        aReporter.Report( _( "Could not open archive file." ), RPT_SEVERITY_ERROR );
+        return false;
+    }
+
+    wxZipInputStream zipStreamA = wxZipInputStream( streamA );
+    wxZipInputStream zipStreamB = wxZipInputStream( streamB );
+
+    std::set<wxUint32> crcsA;
+    std::set<wxUint32> crcsB;
+
+
+    for( wxZipEntry* entry = zipStreamA.GetNextEntry(); entry; entry = zipStreamA.GetNextEntry() )
+    {
+        crcsA.insert( entry->GetCrc() );
+    }
+
+    for( wxZipEntry* entry = zipStreamB.GetNextEntry(); entry; entry = zipStreamB.GetNextEntry() )
+    {
+        crcsB.insert( entry->GetCrc() );
+    }
+
+    return crcsA == crcsB;
+}
+
 
 // Unarchive Files code comes from wxWidgets sample/archive/archive.cpp
 bool PROJECT_ARCHIVER::Unarchive( const wxString& aSrcFile, const wxString& aDestDir,

common/settings/settings_manager.cpp

@@ -1339,17 +1339,36 @@ bool SETTINGS_MANAGER::TriggerBackupIfNeeded( REPORTER& aReporter ) const
                    return first.GetTicks() > second.GetTicks();
                } );
 
-    // Do we even need to back up?
-    if( !files.empty() )
+    // Backup
+    bool backupSuccessful = BackupProject( aReporter );
+    if( !backupSuccessful )
+        return false;
+
+    // Update the file list
+    files.clear();
+    dir.Traverse( traverser, wxT( "*.zip" ) );
+
+    // Sort newest-first
+    std::sort( files.begin(), files.end(),
+               [&]( const wxString& aFirst, const wxString& aSecond ) -> bool
+               {
+                   wxDateTime first = modTime( aFirst );
+                   wxDateTime second = modTime( aSecond );
+
+                   return first.GetTicks() > second.GetTicks();
+               } );
+
+    // Are there any changes since the last backup?
+    if( files.size() > 1 )
     {
-        wxDateTime lastTime = modTime( files[0] );
+        PROJECT_ARCHIVER archiver;
+        bool             identicalToPrevious =
+                archiver.AreZipArchivesIdentical( files[0], files[1], aReporter );
 
-        if( lastTime.IsValid() )
+        if( identicalToPrevious )
         {
-            wxTimeSpan delta = wxDateTime::Now() - modTime( files[0] );
-
-            if( delta.IsShorterThan( wxTimeSpan::Seconds( settings.min_interval ) ) )
-                return true;
+            wxRemoveFile( files[0] );
+            return true;
         }
     }
 
@@ -1413,7 +1432,7 @@ bool SETTINGS_MANAGER::TriggerBackupIfNeeded( REPORTER& aReporter ) const
             wxRemoveFile( file );
     }
 
-    return BackupProject( aReporter );
+    return true;
 }
 
 

include/project/project_archiver.h

@@ -36,6 +36,16 @@ public:
 
     ~PROJECT_ARCHIVER() = default;
 
+    /**
+     * Compares the crcs of all the files in zip archive to determine whether the archives are identical
+     * @param aZipFileA is the full path to the first zip
+     * @param aZipFileB is the full path to the second zip
+     * @param aReporter is used to report status
+     * @return true if the archives are identical
+     */
+    bool AreZipArchivesIdentical( const wxString& aZipFileA, const wxString& aZipFileB,
+                                  REPORTER& aReporter );
+
     /**
      * Creates an archive of the project
      * @param aSrcFile is the full path to the project to be archived