From e523b43b7e394950126b379f87914ce57afed154 Mon Sep 17 00:00:00 2001
From: Lukas Eder <lukas.eder@gmail.com>
Date: Wed, 18 Aug 2021 16:36:03 +0200
Subject: [PATCH] [jOOQ/jOOQ#12328] Empty select() should not project asterisk
 if unknown table is used with leftSemiJoin() or leftAntiJoin()

---
 .../java/org/jooq/impl/DeleteQueryImpl.java   |  2 +-
 .../java/org/jooq/impl/SelectQueryImpl.java   | 15 +++++-
 jOOQ/src/main/java/org/jooq/impl/Tools.java   | 49 ++++++++++++++-----
 3 files changed, 52 insertions(+), 14 deletions(-)

diff --git a/jOOQ/src/main/java/org/jooq/impl/DeleteQueryImpl.java b/jOOQ/src/main/java/org/jooq/impl/DeleteQueryImpl.java
index f32b20c391..c91153fa8e 100644
--- a/jOOQ/src/main/java/org/jooq/impl/DeleteQueryImpl.java
+++ b/jOOQ/src/main/java/org/jooq/impl/DeleteQueryImpl.java
@@ -237,7 +237,7 @@ final class DeleteQueryImpl<R extends Record> extends AbstractDMLQuery<R> implem
         if (multiTableJoin)
 
             // No table declarations in this case, but references
-            ctx.visit(K_FROM).sql(' ').visit(traverseJoins(t, new TableList(), x -> false, (r, x) -> { r.add(x); return r; })).formatSeparator();
+            ctx.visit(K_FROM).sql(' ').visit(traverseJoins(t, new TableList(), null, (r, x) -> { r.add(x); return r; })).formatSeparator();
 
 
 
diff --git a/jOOQ/src/main/java/org/jooq/impl/SelectQueryImpl.java b/jOOQ/src/main/java/org/jooq/impl/SelectQueryImpl.java
index bf4360ac5e..c91c510ffb 100644
--- a/jOOQ/src/main/java/org/jooq/impl/SelectQueryImpl.java
+++ b/jOOQ/src/main/java/org/jooq/impl/SelectQueryImpl.java
@@ -3815,7 +3815,20 @@ final class SelectQueryImpl<R extends Record> extends AbstractResultQuery<R> imp
     }
 
     private final boolean knownTableSource() {
-        return traverseJoins(getFrom(), true, r -> !r, (r, t) -> r && t.fieldsRow().size() > 0);
+        return traverseJoins(
+            getFrom(),
+            true,
+            r -> !r,
+            null,
+
+            // [#12328] Don't recurse into the RHS if the join does not affect the projection
+            j -> j.type != JoinType.LEFT_ANTI_JOIN && j.type != JoinType.LEFT_SEMI_JOIN,
+            null,
+            
+            // TODO: PostgreSQL supports tables without columns, see e.g.
+            // https://blog.jooq.org/creating-tables-dum-and-dee-in-postgresql/
+            (r, t) -> r && t.fieldsRow().size() > 0
+        );
     }
 
     @SuppressWarnings("unchecked")
diff --git a/jOOQ/src/main/java/org/jooq/impl/Tools.java b/jOOQ/src/main/java/org/jooq/impl/Tools.java
index 7ebd27f092..f849c2f752 100644
--- a/jOOQ/src/main/java/org/jooq/impl/Tools.java
+++ b/jOOQ/src/main/java/org/jooq/impl/Tools.java
@@ -6260,7 +6260,7 @@ final class Tools {
     }
 
     static final void traverseJoins(Table<?> t, Consumer<? super Table<?>> consumer) {
-        traverseJoins(t, null, x -> false, (result, x) -> { consumer.accept(x); return result; });
+        traverseJoins(t, null, null, (result, x) -> { consumer.accept(x); return result; });
     }
 
     static final <T> T traverseJoins(
@@ -6270,7 +6270,7 @@ final class Tools {
         BiFunction<? super T, ? super Table<?>, ? extends T> function
     ) {
         for (Table<?> t : i)
-            if (abort.test(result))
+            if (abort != null && abort.test(result))
                 return result;
             else
                 result = traverseJoins(t, result, abort, function);
@@ -6284,33 +6284,58 @@ final class Tools {
         Predicate<? super T> abort,
         BiFunction<? super T, ? super Table<?>, ? extends T> function
     ) {
-        return traverseJoins(t, result, abort, null, function);
+        return traverseJoins(t, result, abort, null, null, null, function);
+    }
+
+    static final <T> T traverseJoins(
+        Iterable<? extends Table<?>> i,
+        T result,
+        Predicate<? super T> abort,
+        Predicate<? super JoinTable> recurseLhs,
+        Predicate<? super JoinTable> recurseRhs,
+        BiFunction<? super T, ? super JoinType, ? extends T> joinTypeFunction,
+        BiFunction<? super T, ? super Table<?>, ? extends T> tableFunction
+    ) {
+        for (Table<?> t : i)
+            if (abort != null && abort.test(result))
+                return result;
+            else
+                result = traverseJoins(t, result, abort, recurseLhs, recurseRhs, joinTypeFunction, tableFunction);
+
+        return result;
     }
 
     static final <T> T traverseJoins(
         Table<?> t,
         T result,
         Predicate<? super T> abort,
+        Predicate<? super JoinTable> recurseLhs,
+        Predicate<? super JoinTable> recurseRhs,
         BiFunction<? super T, ? super JoinType, ? extends T> joinTypeFunction,
         BiFunction<? super T, ? super Table<?>, ? extends T> tableFunction
     ) {
-        if (abort.test(result))
+        if (abort != null && abort.test(result))
             return result;
 
         if (t instanceof JoinTable) {
-            result = traverseJoins(((JoinTable) t).lhs, result, abort, joinTypeFunction, tableFunction);
+            JoinTable j = (JoinTable) t;
 
-            if (abort.test(result))
-                return result;
+            if (recurseLhs == null || recurseLhs.test(j)) {
+                result = traverseJoins(j.lhs, result, abort, recurseLhs, recurseRhs, joinTypeFunction, tableFunction);
 
-            if (joinTypeFunction != null) {
-                result = joinTypeFunction.apply(result, ((JoinTable) t).type);
-
-                if (abort.test(result))
+                if (abort != null && abort.test(result))
                     return result;
             }
 
-            result = traverseJoins(((JoinTable) t).rhs, result, abort, joinTypeFunction, tableFunction);
+            if (joinTypeFunction != null) {
+                result = joinTypeFunction.apply(result, j.type);
+
+                if (abort != null && abort.test(result))
+                    return result;
+            }
+
+            if (recurseRhs == null || recurseRhs.test(j))
+                result = traverseJoins(j.rhs, result, abort, recurseLhs, recurseRhs, joinTypeFunction, tableFunction);
         }
         else if (tableFunction != null)
             result = tableFunction.apply(result, t);