fix(trace): Error with overlapping span ids (#94565)

- Because this was a dict with single errors the trace would lose errors
if there were multiple errors for a given span id

Author: wmak

src/sentry/api/endpoints/organization_trace.py

@@ -286,7 +286,9 @@ def query_trace_data(self, snuba_params: SnubaParams, trace_id: str) -> list[Ser
 
         result = []
         id_to_span = {event["id"]: event for event in spans_data}
-        id_to_error = {event["trace.span"]: event for event in errors_data}
+        id_to_error: dict[str, Any] = {}
+        for event in errors_data:
+            id_to_error.setdefault(event["trace.span"], []).append(event)
         id_to_occurrence = defaultdict(list)
         with sentry_sdk.start_span(op="process.occurrence_data") as sdk_span:
             for event in occurrence_data:
@@ -302,8 +304,8 @@ def query_trace_data(self, snuba_params: SnubaParams, trace_id: str) -> list[Ser
             else:
                 result.append(span)
             if span["id"] in id_to_error:
-                error = id_to_error.pop(span["id"])
-                span["errors"].append(error)
+                errors = id_to_error.pop(span["id"])
+                span["errors"].extend(errors)
             if span["id"] in id_to_occurrence:
                 span["occurrences"].extend(
                     [
@@ -315,8 +317,8 @@ def query_trace_data(self, snuba_params: SnubaParams, trace_id: str) -> list[Ser
                         for occurrence in id_to_occurrence[span["id"]]
                     ]
                 )
-        for error in id_to_error.values():
-            result.append(error)
+        for errors in id_to_error.values():
+            result.extend(errors)
         return [self.serialize_rpc_event(root) for root in result]
 
     def has_feature(self, organization: Organization, request: Request) -> bool:

tests/snuba/api/endpoints/test_organization_trace.py

@@ -159,6 +159,37 @@ def test_with_errors_data(self):
         assert error_event["issue_id"] == error.group_id
         assert error_event["start_timestamp"] == error_data["timestamp"]
 
+    def test_with_errors_data_with_overlapping_span_id(self):
+        self.load_trace(is_eap=True)
+        _, start = self.get_start_end_from_day_ago(123)
+        error_data = load_data(
+            "javascript",
+            timestamp=start,
+        )
+        error_data["contexts"]["trace"] = {
+            "type": "trace",
+            "trace_id": self.trace_id,
+            "span_id": self.root_event.data["contexts"]["trace"]["span_id"],
+        }
+        error_data["tags"] = [["transaction", "/transaction/gen1-0"]]
+        error = self.store_event(error_data, project_id=self.gen1_project.id)
+        error_2 = self.store_event(error_data, project_id=self.gen1_project.id)
+
+        with self.feature(self.FEATURES):
+            response = self.client_get(
+                data={"timestamp": self.day_ago},
+            )
+        assert response.status_code == 200, response.content
+        data = response.data
+        assert len(data) == 1
+        self.assert_trace_data(data[0])
+        assert len(data[0]["errors"]) == 2
+        error_event_1 = data[0]["errors"][0]
+        error_event_2 = data[0]["errors"][1]
+        assert error_event_1["event_id"] in [error.event_id, error_2.event_id]
+        assert error_event_2["event_id"] in [error.event_id, error_2.event_id]
+        assert error_event_1["event_id"] != error_event_2["event_id"]
+
     def test_with_performance_issues(self):
         self.load_trace(is_eap=True)
         with self.feature(self.FEATURES):