handle multiple patterns in initCrossClusterState

Author: idegtiarenko

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/index/IndexResolution.java

@@ -36,6 +36,10 @@ public static IndexResolution valid(EsIndex index) {
         return valid(index, index.concreteIndices(), Map.of());
     }
 
+    public static IndexResolution empty(String indexPattern) {
+        return valid(new EsIndex(indexPattern, Map.of(), Map.of(), Set.of()));
+    }
+
     public static IndexResolution invalid(String invalid) {
         Objects.requireNonNull(invalid, "invalid must not be null to signal that the index is invalid");
         return new IndexResolution(null, invalid, Set.of(), Map.of());

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/session/EsqlCCSUtils.java

@@ -325,33 +325,29 @@ public static void initCrossClusterState(
             return;
         }
         try {
-            // TODO it is not safe to concat multiple index patterns in case any of them contains exclusion.
-            // This is going to be resolved in #136804
-            String[] indexExpressions = indexPatterns.stream()
-                .map(indexPattern -> Strings.splitStringByCommaToArray(indexPattern.indexPattern()))
-                .reduce((a, b) -> {
-                    String[] combined = new String[a.length + b.length];
-                    System.arraycopy(a, 0, combined, 0, a.length);
-                    System.arraycopy(b, 0, combined, a.length, b.length);
-                    return combined;
-                })
-                .get();
-            var groupedIndices = indicesGrouper.groupIndices(IndicesOptions.DEFAULT, indexExpressions, false);
+            for (IndexPattern indexPattern : indexPatterns) {
+                var groupedIndices = indicesGrouper.groupIndices(
+                    IndicesOptions.DEFAULT,
+                    Strings.splitStringByCommaToArray(indexPattern.indexPattern()),
+                    false
+                );
 
-            executionInfo.clusterInfoInitializing(true);
-            // initialize the cluster entries in EsqlExecutionInfo before throwing the invalid license error
-            // so that the CCS telemetry handler can recognize that this error is CCS-related
-            try {
-                for (var entry : groupedIndices.entrySet()) {
-                    final String clusterAlias = entry.getKey();
-                    final String indexExpr = Strings.arrayToCommaDelimitedString(entry.getValue().indices());
-                    executionInfo.swapCluster(clusterAlias, (k, v) -> {
-                        assert v == null : "No cluster for " + clusterAlias + " should have been added to ExecutionInfo yet";
-                        return new EsqlExecutionInfo.Cluster(clusterAlias, indexExpr, executionInfo.shouldSkipOnFailure(clusterAlias));
+                executionInfo.clusterInfoInitializing(true);
+                // initialize the cluster entries in EsqlExecutionInfo before throwing the invalid license error
+                // so that the CCS telemetry handler can recognize that this error is CCS-related
+                try {
+                    groupedIndices.forEach((clusterAlias, indices) -> {
+                        executionInfo.swapCluster(clusterAlias, (k, v) -> {
+                            var indexExpr = Strings.arrayToCommaDelimitedString(indices.indices());
+                            if (v != null) {
+                                indexExpr = v.getIndexExpression() + "," + indexExpr;
+                            }
+                            return new EsqlExecutionInfo.Cluster(clusterAlias, indexExpr, executionInfo.shouldSkipOnFailure(clusterAlias));
+                        });
                     });
+                } finally {
+                    executionInfo.clusterInfoInitializing(false);
                 }
-            } finally {
-                executionInfo.clusterInfoInitializing(false);
             }
 
             if (executionInfo.isCrossClusterSearch() && EsqlLicenseChecker.isCcsAllowed(licenseState) == false) {

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/session/EsqlSession.java

@@ -835,12 +835,9 @@ private void preAnalyzeMainIndices(
             ThreadPool.Names.SEARCH_COORDINATION,
             ThreadPool.Names.SYSTEM_READ
         );
-        // TODO: This is not yet index specific, but that will not matter as soon as #136804 is dealt with
         if (executionInfo.clusterAliases().isEmpty()) {
             // return empty resolution if the expression is pure CCS and resolved no remote clusters (like no-such-cluster*:index)
-            listener.onResponse(
-                result.withIndices(indexPattern, IndexResolution.valid(new EsIndex(indexPattern.indexPattern(), Map.of(), Map.of())))
-            );
+            listener.onResponse(result.withIndices(indexPattern, IndexResolution.empty(indexPattern.indexPattern())));
         } else {
             indexResolver.resolveAsMergedMappingAndRetrieveMinimumVersion(
                 indexPattern.indexPattern(),