[bugfix] status refresh race condition causing double edit notifications (#4470)

# Description

fixes possible race condition of existing status being out-of-date in enrichStatus()

## Checklist

- [x] I/we have read the [GoToSocial contribution guidelines](https://codeberg.org/superseriousbusiness/gotosocial/src/branch/main/CONTRIBUTING.md).
- [x] I/we have discussed the proposed changes already, either in an issue on the repository, or in the Matrix chat.
- [x] I/we have not leveraged AI to create the proposed changes.
- [x] I/we have performed a self-review of added code.
- [x] I/we have written code that is legible and maintainable by others.
- [x] I/we have commented the added code, particularly in hard-to-understand areas.
- [ ] I/we have made any necessary changes to documentation.
- [x] I/we have added tests that cover new code.
- [x] I/we have run tests and they pass locally with the changes.
- [x] I/we have run `go fmt ./...` and `golangci-lint run`.

Reviewed-on: https://codeberg.org/superseriousbusiness/gotosocial/pulls/4470
Co-authored-by: kim <grufwub@gmail.com>
Co-committed-by: kim <grufwub@gmail.com>

1 files changed, 20 insertions, 17 deletions

diff --git a/internal/federation/dereferencing/status.go b/internal/federation/dereferencing/status.go
index 0e86dca7c..fffaa88a6 100644
--- a/internal/federation/dereferencing/status.go
+++ b/internal/federation/dereferencing/status.go
@@ -277,25 +277,30 @@ func (d *Dereferencer) enrichStatusSafely(
 ) (*gtsmodel.Status, ap.Statusable, bool, error) {
 	uriStr := status.URI
 
+	// Acquire per-URI deref lock, wraping unlock
+	// to safely defer in case of panic, while still
+	// performing more granular unlocks when needed.
+	unlock := d.state.FedLocks.Lock(uriStr)
+	unlock = util.DoOnce(unlock)
+	defer unlock()
+
+	var err error
 	var isNew bool
 
 	// Check if this is a new status (to us).
 	if isNew = (status.ID == ""); !isNew {
 
-		// This is an existing status, first try to populate it. This
-		// is required by the checks below for existing tags, media etc.
-		if err := d.state.DB.PopulateStatus(ctx, status); err != nil {
-			log.Errorf(ctx, "error populating existing status %s: %v", uriStr, err)
+		// We reload the existing status, just to ensure we have the
+		// latest version of it. e.g. another racing thread might have
+		// just input a change but we still have an old status copy.
+		//
+		// Note: returned status will be fully populated, required below.
+		status, err = d.state.DB.GetStatusByID(ctx, status.ID)
+		if err != nil {
+			return nil, nil, false, gtserror.Newf("error getting up-to-date existing status: %w", err)
 		}
 	}
 
-	// Acquire per-URI deref lock, wraping unlock
-	// to safely defer in case of panic, while still
-	// performing more granular unlocks when needed.
-	unlock := d.state.FedLocks.Lock(uriStr)
-	unlock = util.DoOnce(unlock)
-	defer unlock()
-
 	// Perform status enrichment with passed vars.
 	latest, statusable, err := d.enrichStatus(ctx,
 		requestUser,
@@ -479,12 +484,10 @@ func (d *Dereferencer) enrichStatus(
 
 	// Ensure the final parsed status URI or URL matches
 	// the input URI we fetched (or received) it as.
-	matches, err := util.URIMatches(uri,
-		append(
-			ap.GetURL(statusable),      // status URL(s)
-			ap.GetJSONLDId(statusable), // status URI
-		)...,
-	)
+	matches, err := util.URIMatches(uri, append(
+		ap.GetURL(statusable),      // status URL(s)
+		ap.GetJSONLDId(statusable), // status URI
+	)...)
 	if err != nil {
 		return nil, nil, gtserror.Newf(
 			"error checking dereferenced status uri %s: %w",