Add an explicit version number to the edits schema

data/system/proposals/cap hill superblock.json

@@ -1,6 +1,7 @@
 {
   "map_name": "downtown",
   "edits_name": "cap hill superblock",
+  "version": 0,
   "commands": [
     {
       "ChangeLaneType": {

data/system/proposals/repair west seattle bridge.json

@@ -1,6 +1,7 @@
 {
   "map_name": "west_seattle",
   "edits_name": "repair west seattle bridge",
+  "version": 0,
   "commands": [
     {
       "ChangeLaneType": {

data/system/proposals/simplify burke corliss.json

@@ -1,6 +1,7 @@
 {
   "map_name": "udistrict",
   "edits_name": "simplify where Corliss, Pacific, and the Burke cross",
+  "version": 0,
   "commands": [
     {
       "ChangeLaneType": {

data/system/proposals/stay healthy lake wash blvd.json

@@ -1,6 +1,7 @@
 {
   "map_name": "lakeslice",
   "edits_name": "stay healthy lake wash blvd",
+  "version": 0,
   "commands": [
     {
       "ChangeLaneType": {

game/src/edit/mod.rs

@@ -31,7 +31,7 @@ use ezgui::{
     Widget,
 };
 use geom::Speed;
-use map_model::{EditCmd, IntersectionID, LaneID, LaneType, MapEdits, PermanentMapEdits};
+use map_model::{EditCmd, IntersectionID, LaneID, LaneType, MapEdits};
 use maplit::btreeset;
 use sim::DontDrawAgents;
 use std::collections::BTreeSet;
@@ -414,15 +414,10 @@ impl LoadEdits {
         // common use case.
         let mut proposals = vec![Line("Community proposals").small_heading().draw(ctx)];
         // Up-front filter out proposals that definitely don't fit the current map
-        for (name, perma) in
-            abstutil::load_all_objects::<PermanentMapEdits>(abstutil::path("system/proposals"))
-        {
-            if PermanentMapEdits::from_permanent(perma, &app.primary.map).is_ok() {
-                proposals.push(Btn::text_fg(&name).build(
-                    ctx,
-                    abstutil::path(format!("system/proposals/{}.json", name)),
-                    None,
-                ));
+        for name in abstutil::list_all_objects(abstutil::path("system/proposals")) {
+            let path = abstutil::path(format!("system/proposals/{}.json", name));
+            if MapEdits::load(&app.primary.map, path.clone(), &mut Timer::throwaway()).is_ok() {
+                proposals.push(Btn::text_fg(&name).build(ctx, path, None));
             }
         }
 

map_model/src/edits/compat.rs

@@ -9,10 +9,19 @@ use serde_json::Value;
 // example, protobufs wouldn't have helped with the fix_intersection_ids problem. Explicit
 // transformation is easier!
 pub fn upgrade(mut value: Value) -> Result<PermanentMapEdits, String> {
-    // I don't remember the previous schema change before this. If someone files a bug and has an
-    // older file, can add support for it then.
-    fix_offset(&mut value);
-    fix_intersection_ids(&mut value);
+    // c46a74f10f4f1976a48aa8642ac11717d74b262c added an explicit version field. There are a few
+    // changes before that.
+    if value.get("version").is_none() {
+        // I don't remember the previous schema change before this. If someone files a bug and has
+        // an older file, can add support for it then.
+        fix_offset(&mut value);
+        fix_intersection_ids(&mut value);
+
+        value
+            .as_object_mut()
+            .unwrap()
+            .insert("version".to_string(), Value::Number(0.into()));
+    }
 
     abstutil::from_json(&value.to_string().into_bytes()).map_err(|x| x.to_string())
 }

map_model/src/edits/perma.rs

@@ -12,6 +12,7 @@ use std::collections::{BTreeMap, BTreeSet};
 pub struct PermanentMapEdits {
     pub map_name: String,
     pub edits_name: String,
+    pub version: usize,
     commands: Vec<PermanentEditCmd>,
 
     // Edits without these are player generated.
@@ -82,6 +83,8 @@ impl PermanentMapEdits {
         PermanentMapEdits {
             map_name: map.get_name().to_string(),
             edits_name: edits.edits_name.clone(),
+            // Increase this every time there's a schema change
+            version: 0,
             proposal_description: edits.proposal_description.clone(),
             proposal_link: edits.proposal_link.clone(),
             commands: edits