https://sqlite.org/cgi/src/info/9d0d4ab95dc0c56e
https://sqlite.org/cgi/src/info/abc473fb8fb99900
https://sqlite.org/cgi/src/info/5aeb5a2d295e10d5
https://sqlite.org/cgi/src/info/a67cf5b7d37d5b14
https://sqlite.org/cgi/src/info/14d14eb537075c6a
https://sqlite.org/cgi/src/info/c431b3fd8fd0f6a6

--- /src/expr.c
+++ /src/expr.c
@@ -5463,19 +5463,25 @@
     case TK_LT:
     case TK_LE:
     case TK_GT:
-    case TK_GE:
+    case TK_GE: {
+      Expr *pLeft = pExpr->pLeft;
+      Expr *pRight = pExpr->pRight;
       testcase( pExpr->op==TK_EQ );
       testcase( pExpr->op==TK_NE );
       testcase( pExpr->op==TK_LT );
       testcase( pExpr->op==TK_LE );
       testcase( pExpr->op==TK_GT );
       testcase( pExpr->op==TK_GE );
-      if( (pExpr->pLeft->op==TK_COLUMN && IsVirtual(pExpr->pLeft->y.pTab))
-       || (pExpr->pRight->op==TK_COLUMN && IsVirtual(pExpr->pRight->y.pTab))
+      /* The y.pTab=0 assignment in wherecode.c always happens after the
+      ** impliesNotNullRow() test */
+      if( (pLeft->op==TK_COLUMN && ALWAYS(pLeft->y.pTab!=0)
+                               && IsVirtual(pLeft->y.pTab))
+       || (pRight->op==TK_COLUMN && ALWAYS(pRight->y.pTab!=0)
+                               && IsVirtual(pRight->y.pTab))
       ){
-       return WRC_Prune;
+        return WRC_Prune;
       }
-
+    }
     default:
       return WRC_Continue;
   }
--- /src/resolve.c
+++ /src/resolve.c
@@ -1051,7 +1051,7 @@
       assert( !ExprHasProperty(pExpr, EP_Reduced) );
       /* Handle special cases of "x IS TRUE", "x IS FALSE", "x IS NOT TRUE",
       ** and "x IS NOT FALSE". */
-      if( pRight->op==TK_ID ){
+      if( pRight && pRight->op==TK_ID ){
         int rc = resolveExprStep(pWalker, pRight);
         if( rc==WRC_Abort ) return WRC_Abort;
         if( pRight->op==TK_TRUEFALSE ){
--- /src/select.c
+++ /src/select.c
@@ -2806,6 +2806,7 @@
         /* Generate code to take the intersection of the two temporary
         ** tables.
         */
+        if( rc ) break;
         assert( p->pEList );
         iBreak = sqlite3VdbeMakeLabel(pParse);
         iCont = sqlite3VdbeMakeLabel(pParse);
@@ -5148,7 +5149,7 @@
             pNew = sqlite3ExprListAppend(pParse, pNew, pExpr);
             sqlite3TokenInit(&sColname, zColname);
             sqlite3ExprListSetName(pParse, pNew, &sColname, 0);
-            if( pNew && (p->selFlags & SF_NestedFrom)!=0 ){
+            if( pNew && (p->selFlags & SF_NestedFrom)!=0 && !IN_RENAME_OBJECT ){
               struct ExprList_item *pX = &pNew->a[pNew->nExpr-1];
               sqlite3DbFree(db, pX->zEName);
               if( pSub ){
--- /src/sqliteInt.h
+++ /src/sqliteInt.h
@@ -2153,8 +2153,11 @@
 */
 #ifndef SQLITE_OMIT_VIRTUALTABLE
 #  define IsVirtual(X)      ((X)->nModuleArg)
+#  define ExprIsVtab(X)  \
+              ((X)->op==TK_COLUMN && (X)->y.pTab!=0 && (X)->y.pTab->nModuleArg)
 #else
 #  define IsVirtual(X)      0
+#  define ExprIsVtab(X)     0
 #endif
 
 /*
--- /src/whereexpr.c
+++ /src/whereexpr.c
@@ -377,7 +377,8 @@
     **       MATCH(expression,vtab_column)
     */
     pCol = pList->a[1].pExpr;
-    if( pCol->op==TK_COLUMN && IsVirtual(pCol->y.pTab) ){
+    testcase( pCol->op==TK_COLUMN && pCol->y.pTab==0 );
+    if( ExprIsVtab(pCol) ){
       for(i=0; i<ArraySize(aOp); i++){
         if( sqlite3StrICmp(pExpr->u.zToken, aOp[i].zOp)==0 ){
           *peOp2 = aOp[i].eOp2;
@@ -399,7 +400,8 @@
     ** with function names in an arbitrary case.
     */
     pCol = pList->a[0].pExpr;
-    if( pCol->op==TK_COLUMN && IsVirtual(pCol->y.pTab) ){
+    testcase( pCol->op==TK_COLUMN && pCol->y.pTab==0 );
+    if( ExprIsVtab(pCol) ){
       sqlite3_vtab *pVtab;
       sqlite3_module *pMod;
       void (*xNotUsed)(sqlite3_context*,int,sqlite3_value**);
@@ -422,10 +424,12 @@
     int res = 0;
     Expr *pLeft = pExpr->pLeft;
     Expr *pRight = pExpr->pRight;
-    if( pLeft->op==TK_COLUMN && IsVirtual(pLeft->y.pTab) ){
+    testcase( pLeft->op==TK_COLUMN && pLeft->y.pTab==0 );
+    if( ExprIsVtab(pLeft) ){
       res++;
     }
-    if( pRight && pRight->op==TK_COLUMN && IsVirtual(pRight->y.pTab) ){
+    testcase( pRight && pRight->op==TK_COLUMN && pRight->y.pTab==0 );
+    if( pRight && ExprIsVtab(pRight) ){
       res++;
       SWAP(Expr*, pLeft, pRight);
     }
--- /test/altertab.test
+++ /test/altertab.test
@@ -613,4 +613,21 @@
   SELECT sql FROM sqlite_master;
 } {{CREATE TABLE t0 (c1 INTEGER, PRIMARY KEY(c1))}}
 
+# 2020-02-23 ticket f50af3e8a565776b
+reset_db
+do_execsql_test 19.100 {
+  CREATE TABLE t1(x);
+  CREATE VIEW t2 AS SELECT 1 FROM t1, (t1 AS a0, t1);
+  ALTER TABLE t1 RENAME TO t3;
+  SELECT sql FROM sqlite_master;
+} {{CREATE TABLE "t3"(x)} {CREATE VIEW t2 AS SELECT 1 FROM "t3", ("t3" AS a0, "t3")}}
+do_execsql_test 19.110 {
+  INSERT INTO t3(x) VALUES(123);
+  SELECT * FROM t2;
+} {1}
+do_execsql_test 19.120 {
+  INSERT INTO t3(x) VALUES('xyz');
+  SELECT * FROM t2;
+} {1 1 1 1 1 1 1 1}
+
 finish_test
--- /test/windowfault.test
+++ /test/windowfault.test
@@ -263,4 +263,15 @@
   faultsim_test_result {0 {}}
 }
 
+do_faultsim_test 11 -faults oom* -prep {
+} -body {
+  execsql {
+    VALUES(false),(current_date collate binary) 
+    intersect 
+    values(count() not like group_concat(cast(cast(0e00 as text) as integer) <= NULL || 0.4e-0 || 0x8 & true ) over () collate rtrim);
+  }
+} -test {
+  faultsim_test_result {0 {}}
+}
+
 finish_test