From faaacd3fbb6088b1faedf1536b2366db0fb87ea3 Mon Sep 17 00:00:00 2001
From: drh <>
Date: Wed, 21 Sep 2022 00:16:59 +0000
Subject: [PATCH] Break out the decision of whether or not a constraint term is
 usable by an outer join into a subroutine:
 constraintCompatibleWithOuterJoin().

FossilOrigin-Name: c7fbc9b0453050e2746af27e3a11e0c3701bef8c56da8e19173242c6ea3aff8b
---
 manifest      | 12 ++++----
 manifest.uuid |  2 +-
 src/where.c   | 81 ++++++++++++++++++++++++++++-----------------------
 3 files changed, 51 insertions(+), 44 deletions(-)

diff --git a/manifest b/manifest
index 34a771310d..40c1bb24e9 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Do\snot\sallow\sEP_InnerON\sterms\sto\sbe\sused\son\sa\souter\sjoin.
-D 2022-09-20T22:19:13.998
+C Break\sout\sthe\sdecision\sof\swhether\sor\snot\sa\sconstraint\sterm\sis\susable\sby\nan\souter\sjoin\sinto\sa\ssubroutine:\sconstraintCompatibleWithOuterJoin().
+D 2022-09-21T00:16:59.294
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -675,7 +675,7 @@ F src/vxworks.h d2988f4e5a61a4dfe82c6524dd3d6e4f2ce3cdb9
 F src/wal.c b9df133a705093da8977da5eb202eaadb844839f1c7297c08d33471f5491843d
 F src/wal.h c3aa7825bfa2fe0d85bef2db94655f99870a285778baa36307c0a16da32b226a
 F src/walker.c f890a3298418d7cba3b69b8803594fdc484ea241206a8dfa99db6dd36f8cbb3b
-F src/where.c 075de11bb3a7be19cfe27e104d52e19d30096925ef2524341bf5a6bfcdbc4127
+F src/where.c 3774d9831a6f4ac81f201fa9e2ec1bb40c99b7207dce7663c2e39fb73cc1bfd5
 F src/whereInt.h 70cd30de9ed784aa33fa6bd1245f060617de7a00d992469b6d8e419eed915743
 F src/wherecode.c 6bb1cf9d0a4e3e04dab0bf0ea4a8d936a0dcc05a7e2207beeda6c61aea6dd341
 F src/whereexpr.c 55a39f42aaf982574fbf52906371a84cceed98a994422198dfd03db4fce4cc46
@@ -2000,8 +2000,8 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P fe5c37736444e397ace387b761ec2491229785d7a437f3f60232aedf9d1f00ec
-R b7bb9d0f74cad7fddb9b6178bd7d10bc
+P f47aa745690c018800243bf76930b2499ff4537411c4e27b4b16ba3854cc2bf8
+R ffb250842cc4325c51d9fb2f2a7cd199
 U drh
-Z 62c9c805d4ceaa75bf6aed42a5148e09
+Z 35e62397d6a559d77545ee94797c3cd6
 # Remove this line to create a well-formed Fossil manifest.
diff --git a/manifest.uuid b/manifest.uuid
index 0c5527bedd..dc64e5b341 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-f47aa745690c018800243bf76930b2499ff4537411c4e27b4b16ba3854cc2bf8
\ No newline at end of file
+c7fbc9b0453050e2746af27e3a11e0c3701bef8c56da8e19173242c6ea3aff8b
\ No newline at end of file
diff --git a/src/where.c b/src/where.c
index 2105c4c035..5811d830d1 100644
--- a/src/where.c
+++ b/src/where.c
@@ -743,6 +743,38 @@ static void whereTraceIndexInfoOutputs(sqlite3_index_info *p){
 #define whereTraceIndexInfoOutputs(A)
 #endif
 
+/*
+** We know that pSrc is an operand of an outer join.  Return true if
+** pTerm is a constraint that is compatible with that join.
+**
+** pTerm must be EP_OuterON if pSrc is the right operand of an
+** outer join.  pTerm can be either EP_OuterON or EP_InnerON if pSrc
+** is the left operand of a RIGHT join.
+*/
+static int constraintCompatibleWithOuterJoin(
+  const WhereTerm *pTerm,       /* WHERE clause term to check */
+  const SrcItem *pSrc           /* Table we are trying to access */
+){
+  assert( (pSrc->fg.jointype&(JT_LEFT|JT_LTORJ|JT_RIGHT))!=0 ); /* By caller */
+  testcase( (pSrc->fg.jointype & (JT_LEFT|JT_LTORJ|JT_RIGHT))==JT_LEFT );
+  testcase( (pSrc->fg.jointype & (JT_LEFT|JT_LTORJ|JT_RIGHT))==JT_LTORJ );
+  testcase( ExprHasProperty(pTerm->pExpr, EP_OuterON) )
+  testcase( ExprHasProperty(pTerm->pExpr, EP_InnerON) );
+  if( !ExprHasProperty(pTerm->pExpr, EP_OuterON|EP_InnerON)
+   || pTerm->pExpr->w.iJoin != pSrc->iCursor
+  ){
+    return 0;
+  }
+  if( (pSrc->fg.jointype & (JT_LEFT|JT_RIGHT))!=0
+   && ExprHasProperty(pTerm->pExpr, EP_InnerON)
+  ){
+    return 0;
+  }
+  return 1;
+}
+ 
+
+
 #ifndef SQLITE_OMIT_AUTOMATIC_INDEX
 /*
 ** Return TRUE if the WHERE clause term pTerm is of a form where it
@@ -758,16 +790,10 @@ static int termCanDriveIndex(
   if( pTerm->leftCursor!=pSrc->iCursor ) return 0;
   if( (pTerm->eOperator & (WO_EQ|WO_IS))==0 ) return 0;
   assert( (pSrc->fg.jointype & JT_RIGHT)==0 );
-  if( (pSrc->fg.jointype & (JT_LEFT|JT_LTORJ|JT_RIGHT))!=0 ){
-    testcase( (pSrc->fg.jointype & (JT_LEFT|JT_LTORJ|JT_RIGHT))==JT_LEFT );
-    testcase( (pSrc->fg.jointype & (JT_LEFT|JT_LTORJ|JT_RIGHT))==JT_LTORJ );
-    testcase( ExprHasProperty(pTerm->pExpr, EP_OuterON) )
-    testcase( ExprHasProperty(pTerm->pExpr, EP_InnerON) );
-    if( !ExprHasProperty(pTerm->pExpr, EP_OuterON|EP_InnerON)
-     || pTerm->pExpr->w.iJoin != pSrc->iCursor
-    ){
-      return 0;  /* See tag-20191211-001 */
-    }
+  if( (pSrc->fg.jointype & (JT_LEFT|JT_LTORJ|JT_RIGHT))!=0
+   && !constraintCompatibleWithOuterJoin(pTerm,pSrc)
+  ){
+    return 0;
   }
   if( (pTerm->prereqRight & notReady)!=0 ) return 0;
   assert( (pTerm->eOperator & (WO_OR|WO_AND))==0 );
@@ -1184,17 +1210,10 @@ static sqlite3_index_info *allocateIndexInfo(
     ** right-hand table of a LEFT JOIN nor to the either table of a
     ** RIGHT JOIN.  See tag-20191211-001 for the
     ** equivalent restriction for ordinary tables. */
-    if( (pSrc->fg.jointype & (JT_LEFT|JT_LTORJ|JT_RIGHT))!=0 ){
-      testcase( (pSrc->fg.jointype & (JT_LEFT|JT_LTORJ|JT_RIGHT))==JT_LEFT );
-      testcase( (pSrc->fg.jointype & (JT_LEFT|JT_LTORJ|JT_RIGHT))==JT_RIGHT );
-      testcase( (pSrc->fg.jointype & (JT_LEFT|JT_LTORJ|JT_RIGHT))==JT_LTORJ );
-      testcase( ExprHasProperty(pTerm->pExpr, EP_OuterON) );
-      testcase( ExprHasProperty(pTerm->pExpr, EP_InnerON) );
-      if( !ExprHasProperty(pTerm->pExpr, EP_OuterON|EP_InnerON)
-       || pTerm->pExpr->w.iJoin != pSrc->iCursor
-      ){
-        continue;
-      }
+    if( (pSrc->fg.jointype & (JT_LEFT|JT_LTORJ|JT_RIGHT))!=0
+     && !constraintCompatibleWithOuterJoin(pTerm,pSrc)
+    ){
+      continue;
     }
     nTerm++;
     pTerm->wtFlags |= TERM_OK;
@@ -2865,22 +2884,10 @@ static int whereLoopAddBtreeIndex(
     ** 2022-06-10: The same condition applies to termCanDriveIndex() above.
     ** https://sqlite.org/forum/forumpost/51e6959f61
     */
-    if( (pSrc->fg.jointype & (JT_LEFT|JT_LTORJ|JT_RIGHT))!=0 ){
-      testcase( (pSrc->fg.jointype & (JT_LEFT|JT_LTORJ|JT_RIGHT))==JT_LEFT );
-      testcase( (pSrc->fg.jointype & (JT_LEFT|JT_LTORJ|JT_RIGHT))==JT_RIGHT );
-      testcase( (pSrc->fg.jointype & (JT_LEFT|JT_LTORJ|JT_RIGHT))==JT_LTORJ );
-      testcase( ExprHasProperty(pTerm->pExpr, EP_OuterON) )
-      testcase( ExprHasProperty(pTerm->pExpr, EP_InnerON) );
-      if( !ExprHasProperty(pTerm->pExpr, EP_OuterON|EP_InnerON)
-       || pTerm->pExpr->w.iJoin != pSrc->iCursor
-      ){
-        continue;
-      }
-      if( (pSrc->fg.jointype & (JT_LEFT|JT_RIGHT))!=0
-       && ExprHasProperty(pTerm->pExpr, EP_InnerON)
-      ){
-        continue;
-      }
+    if( (pSrc->fg.jointype & (JT_LEFT|JT_LTORJ|JT_RIGHT))!=0
+     && !constraintCompatibleWithOuterJoin(pTerm,pSrc)
+    ){
+      continue;
     }
 
     if( IsUniqueIndex(pProbe) && saved_nEq==pProbe->nKeyCol-1 ){