Preserve authored projection content and contextual canvas selection

crates/oa-core/src/migration_v4.rs

@@ -69,8 +69,8 @@ impl Project4 {
         }
         crate::persistence::check_pre6_relations(self.relations.values())?;
         crate::persistence::check_pre6_elements(self.elements.values())?;
-        Ok(Project {
-            schema_version: SCHEMA_VERSION,
+        let mut project = Project {
+            schema_version: self.schema_version,
             id: self.id,
             alias: self.alias,
             name: self.name,
@@ -84,7 +84,11 @@ impl Project4 {
                 .into_iter()
                 .map(|(id, trace)| (id, trace.into()))
                 .collect(),
-        })
+        };
+        // Schema3's adapter also enters here, without calling `finish`.
+        crate::persistence::check_pre7_diagram_admission(&project)?;
+        project.schema_version = SCHEMA_VERSION;
+        Ok(project)
     }
 }
 
@@ -104,6 +108,8 @@ pub(crate) fn review_defaults(project: &Project, report: &mut MigrationReport) {
 }
 
 pub(crate) fn finish(mut project: Project, limits: ParseLimits) -> Result<DecodeResult, FileError> {
+    // Source4 enters here directly rather than through `Project4`.
+    crate::persistence::check_pre7_diagram_admission(&project)?;
     crate::persistence::check_pre6_relations(project.relations.values())?;
     crate::persistence::check_pre6_elements(project.elements.values())?;
     project.schema_version = SCHEMA_VERSION;