MDL-39177 Update file in filearea only if original is present

Now when file was deleted in filemanager and new file with the same file was uploaded the references will be converted to copies exactly like UI warns in filemanager.
Also do not delete original information from draftfiles.

diff --git a/lib/filelib.php b/lib/filelib.php
index 87bb918..c866841 100644 (file)
--- a/lib/filelib.php
+++ b/lib/filelib.php
@@ -805,6 +805,10 @@ function file_save_draft_area_files($draftitemid, $contextid, $component, $filea
         // there were no files before - one file means root dir only ;-)
         foreach ($draftfiles as $file) {
             $file_record = array('contextid'=>$contextid, 'component'=>$component, 'filearea'=>$filearea, 'itemid'=>$itemid);
+            if ($source = @unserialize($file->get_source())) {
+                // Field files.source for draftarea files contains serialised object with source and original information.
+                $file_record['source'] = $source->source;
+            }
             if (!$options['subdirs']) {
                 if ($file->get_filepath() !== '/' or $file->is_directory()) {
                     continue;
@@ -832,7 +836,6 @@ function file_save_draft_area_files($draftitemid, $contextid, $component, $filea
                     $file_record['reference'] = $file->get_reference();
                 }
             }
-            file_restore_source_field_from_draft_file($file);
 
             $fs->create_file_from_storedfile($file_record, $file);
         }
@@ -844,7 +847,6 @@ function file_save_draft_area_files($draftitemid, $contextid, $component, $filea
         $newhashes = array();
         foreach ($draftfiles as $file) {
             $newhash = $fs->get_pathname_hash($contextid, $component, $filearea, $itemid, $file->get_filepath(), $file->get_filename());
-            file_restore_source_field_from_draft_file($file);
             $newhashes[$newhash] = $file;
         }
         $filecount = 0;
@@ -857,6 +859,25 @@ function file_save_draft_area_files($draftitemid, $contextid, $component, $filea
             }
 
             $newfile = $newhashes[$oldhash];
+            // Now we know that we have $oldfile and $newfile for the same path.
+            // Let's check if we can update this file or we need to delete and create.
+            if ($newfile->is_directory()) {
+                // Directories are always ok to just update.
+            } else if (($source = @unserialize($newfile->get_source())) && isset($source->original)) {
+                // File has the 'original' - we need to update the file (it may even have not been changed at all).
+                $original = file_storage::unpack_reference($source->original);
+                if ($original['filename'] !== $oldfile->get_filename() || $original['filepath'] !== $oldfile->get_filepath()) {
+                    // Very odd, original points to another file. Delete and create file.
+                    $oldfile->delete();
+                    continue;
+                }
+            } else {
+                // The same file name but absence of 'original' means that file was deteled and uploaded again.
+                // By deleting and creating new file we properly manage all existing references.
+                $oldfile->delete();
+                continue;
+            }
+
             // status changed, we delete old file, and create a new one
             if ($oldfile->get_status() != $newfile->get_status()) {
                 // file was changed, use updated with new timemodified data
@@ -875,8 +896,12 @@ function file_save_draft_area_files($draftitemid, $contextid, $component, $filea
             }
 
             // Updated file source
-            if ($oldfile->get_source() != $newfile->get_source()) {
-                $oldfile->set_source($newfile->get_source());
+            $newsource = $newfile->get_source();
+            if ($source = @unserialize($newfile->get_source())) {
+                $newsource = $source->source;
+            }
+            if ($oldfile->get_source() !== $newsource) {
+                $oldfile->set_source($newsource);
             }
 
             // Updated sort order
@@ -893,9 +918,10 @@ function file_save_draft_area_files($draftitemid, $contextid, $component, $filea
                 continue;
             }
             // Replaced file content
-            else if ($oldfile->get_contenthash() != $newfile->get_contenthash() ||
+            if (!$oldfile->is_directory() &&
+                    ($oldfile->get_contenthash() != $newfile->get_contenthash() ||
                     $oldfile->get_filesize() != $newfile->get_filesize() ||
-                    $oldfile->get_referencefileid() != $newfile->get_referencefileid()) {
+                    $oldfile->get_referencefileid() != $newfile->get_referencefileid())) {
                 $oldfile->replace_file_with($newfile);
                 // push changes to all local files that are referencing this file
                 $fs->update_references_to_storedfile($oldfile);
@@ -912,6 +938,10 @@ function file_save_draft_area_files($draftitemid, $contextid, $component, $filea
         // the size and subdirectory tests are extra safety only, the UI should prevent it
         foreach ($newhashes as $file) {
             $file_record = array('contextid'=>$contextid, 'component'=>$component, 'filearea'=>$filearea, 'itemid'=>$itemid, 'timemodified'=>time());
+            if ($source = @unserialize($file->get_source())) {
+                // Field files.source for draftarea files contains serialised object with source and original information.
+                $file_record['source'] = $source->source;
+            }
             if (!$options['subdirs']) {
                 if ($file->get_filepath() !== '/' or $file->is_directory()) {
                     continue;