SQL: Do not resolve self-referencing aliases (elastic#62382)

Prevent the analyzer for trying to resolve aliases on expressions that reference themselves (or fields within themselves) as that causes infinite recursion. Fix elastic#62296 (cherry picked from commit 021d278)
nik9000 · Sep 15, 2020 · b2e85d5 · b2e85d5
1 parent 9ac4ee9
commit b2e85d5
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Showing 2 changed files with 25 additions and 2 deletions.
diff --git a/x-pack/plugin/sql/src/main/java/org/elasticsearch/xpack/sql/analysis/analyzer/Analyzer.java b/x-pack/plugin/sql/src/main/java/org/elasticsearch/xpack/sql/analysis/analyzer/Analyzer.java
@@ -867,7 +867,7 @@ private Expression replaceAliases(Expression condition, List<? extends NamedExpr
                 boolean qualified = u.qualifier() != null;
                 for (Alias alias : aliases) {
                     // don't replace field with their own aliases (it creates infinite cycles)
-                    if (u != alias.child() &&
+                    if (alias.anyMatch(e -> e == u) == false &&
                            (qualified ?
                                Objects.equals(alias.qualifiedName(), u.qualifiedName()) :
                                Objects.equals(alias.name(), u.name()))) {

diff --git a/.../sql/src/test/java/org/elasticsearch/xpack/sql/analysis/analyzer/FieldAttributeTests.java b/.../sql/src/test/java/org/elasticsearch/xpack/sql/analysis/analyzer/FieldAttributeTests.java
@@ -5,7 +5,6 @@
  */
 package org.elasticsearch.xpack.sql.analysis.analyzer;
 
-import java.util.stream.Collectors;
 import org.elasticsearch.test.ESTestCase;
 import org.elasticsearch.xpack.ql.QlIllegalArgumentException;
 import org.elasticsearch.xpack.ql.expression.Alias;
@@ -29,6 +28,7 @@
 
 import java.util.List;
 import java.util.Map;
+import java.util.stream.Collectors;
 
 import static org.elasticsearch.xpack.ql.type.DataTypes.BOOLEAN;
 import static org.elasticsearch.xpack.ql.type.DataTypes.KEYWORD;
@@ -277,4 +277,27 @@ public void testGroupByAmbiguity() {
                 + "matches any of [line 1:37 [m], line 1:55 [m]]",
             ex.getMessage());
     }
+
+    public void testFunctionOverNonExistingFieldAsArgumentAndSameAlias() throws Exception {
+        Map<String, EsField> mapping = TypesTests.loadMapping("mapping-basic.json");
+        EsIndex index = new EsIndex("test", mapping);
+        getIndexResult = IndexResolution.valid(index);
+        analyzer = new Analyzer(SqlTestUtils.TEST_CFG, functionRegistry, getIndexResult, verifier);
+
+        VerificationException ex = expectThrows(VerificationException.class, () ->
+            plan("SELECT sum(missing) AS missing FROM test WHERE missing = 0"));
+        assertEquals("Found 1 problem\nline 1:12: Unknown column [missing]", ex.getMessage());
+    }
+
+    public void testFunctionWithExpressionOverNonExistingFieldAsArgumentAndSameAlias() throws Exception {
+        Map<String, EsField> mapping = TypesTests.loadMapping("mapping-basic.json");
+        EsIndex index = new EsIndex("test", mapping);
+        getIndexResult = IndexResolution.valid(index);
+        analyzer = new Analyzer(SqlTestUtils.TEST_CFG, functionRegistry, getIndexResult, verifier);
+
+        VerificationException ex = expectThrows(VerificationException.class, () ->
+            plan("SELECT LENGTH(CONCAT(missing, 'x')) + 1 AS missing FROM test WHERE missing = 0"));
+        assertEquals("Found 1 problem\nline 1:22: Unknown column [missing]", ex.getMessage());
+    }
+
 }