From: dan <Dan Kennedy>
Date: Wed, 26 May 2021 18:51:57 +0000 (+0000)
Subject: Avoid assuming that an expression like "x=10" in a WHERE clause implies that CASE... 
X-Git-Tag: version-3.36.0~61^2~2
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=40b82f9dc64d6256f3624da044ff4e44a957e540;p=thirdparty%2Fsqlite.git

Avoid assuming that an expression like "x=10" in a WHERE clause implies that CASE(x AS TEXT)=='10'.

FossilOrigin-Name: 389ec669f416c74d651e25572f6e007c2a62ddd4027524f553107b06db5c55eb
---

diff --git a/manifest b/manifest
index 514e2f6f3c..e7ddb5a41f 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Update\san\sassert()\sin\swherecode.c\sthat\smight\sfail\sfollowing\san\sunrelated\sSQL\serror.
-D 2021-05-26T14:32:33.099
+C Avoid\sassuming\sthat\san\sexpression\slike\s"x=10"\sin\sa\sWHERE\sclause\simplies\sthat\sCASE(x\sAS\sTEXT)=='10'.
+D 2021-05-26T18:51:57.863
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -544,7 +544,7 @@ F src/printf.c 78fabb49b9ac9a12dd1c89d744abdc9b67fd3205e62967e158f78b965a29ec4b
 F src/random.c 80f5d666f23feb3e6665a6ce04c7197212a88384
 F src/resolve.c 40e216d9a72e52841a9c8e0aec7d367bade8e2df17b804653b539b20c1ab5660
 F src/rowset.c ba9515a922af32abe1f7d39406b9d35730ed65efab9443dc5702693b60854c92
-F src/select.c 531612539a0058b6e953a5b5497d9a2066f483089764002d9f2745dd7600d6f7
+F src/select.c c4cb9151f29451fb9375c8034b2381f0ec714d2c53c81a70afe959d96b7fc3b6
 F src/shell.c.in 2a2b06d463933ee3a5bb0242d5d2200ca36769493fd6f4d939a0574113f3d6d8
 F src/sqlite.h.in 5c950066775ca9efdaa49077c05d38d0bef6418f3bd07d2dce0210f1d2f3c326
 F src/sqlite3.rc 5121c9e10c3964d5755191c80dd1180c122fc3a8
@@ -1916,7 +1916,10 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 708ce7ad8acee702d08d1987aa253b0bfc3fd97255d6e4153122b03eba337570
-R 2526ebb62b8cafe1a6bcc018fc81592f
+P 3e2c36a8272ab3c1777638c0ed8222e7ff04657fe1c40f74a63b99a5a90258cc
+R cffb4f3f02576d8a42daeb09373618f5
+T *branch * constant-propagation-fix
+T *sym-constant-propagation-fix *
+T -sym-trunk *
 U dan
-Z 78f8b00cbc933cd939f882f5d83b5332
+Z 5eeb8299cfa9877533e1ce28b95ad785
diff --git a/manifest.uuid b/manifest.uuid
index 4d7a5f522c..026f717c4b 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-3e2c36a8272ab3c1777638c0ed8222e7ff04657fe1c40f74a63b99a5a90258cc
\ No newline at end of file
+389ec669f416c74d651e25572f6e007c2a62ddd4027524f553107b06db5c55eb
\ No newline at end of file
diff --git a/src/select.c b/src/select.c
index 42be8554b4..b94cd5364d 100644
--- a/src/select.c
+++ b/src/select.c
@@ -4417,6 +4417,7 @@ struct WhereConst {
   Parse *pParse;   /* Parsing context */
   int nConst;      /* Number for COLUMN=CONSTANT terms */
   int nChng;       /* Number of times a constant is propagated */
+  int bHasAffBlob; /* At least one column in apExpr[] as affinity BLOB */
   Expr **apExpr;   /* [i*2] is COLUMN and [i*2+1] is VALUE */
 };
 
@@ -4455,6 +4456,9 @@ static void constInsert(
       return;  /* Already present.  Return without doing anything. */
     }
   }
+  if( sqlite3ExprAffinity(pColumn)==SQLITE_AFF_BLOB ){
+    pConst->bHasAffBlob = 1;
+  }
 
   pConst->nConst++;
   pConst->apExpr = sqlite3DbReallocOrFree(pConst->pParse->db, pConst->apExpr,
@@ -4496,26 +4500,34 @@ static void findConstInWhere(WhereConst *pConst, Expr *pExpr){
 }
 
 /*
-** This is a Walker expression callback.  pExpr is a candidate expression
-** to be replaced by a value.  If pExpr is equivalent to one of the
-** columns named in pWalker->u.pConst, then overwrite it with its
-** corresponding value.
+** This is a helper function for Walker callback propagateConstantExprRewrite().
+**
+** Argument pExpr is a candidate expression to be replaced by a value. If 
+** pExpr is equivalent to one of the columns named in pWalker->u.pConst, 
+** then overwrite it with the corresponding value. Except, do not do so
+** if argument bIgnoreAffBlob is non-zero and the affinity of pExpr
+** is SQLITE_AFF_BLOB.
 */
-static int propagateConstantExprRewrite(Walker *pWalker, Expr *pExpr){
+static int propagateConstantExprRewriteOne(
+  WhereConst *pConst,
+  Expr *pExpr, 
+  int bIgnoreAffBlob
+){
   int i;
-  WhereConst *pConst;
   if( pExpr->op!=TK_COLUMN ) return WRC_Continue;
   if( ExprHasProperty(pExpr, EP_FixedCol|EP_FromJoin) ){
     testcase( ExprHasProperty(pExpr, EP_FixedCol) );
     testcase( ExprHasProperty(pExpr, EP_FromJoin) );
     return WRC_Continue;
   }
-  pConst = pWalker->u.pConst;
   for(i=0; i<pConst->nConst; i++){
     Expr *pColumn = pConst->apExpr[i*2];
     if( pColumn==pExpr ) continue;
     if( pColumn->iTable!=pExpr->iTable ) continue;
     if( pColumn->iColumn!=pExpr->iColumn ) continue;
+    if( bIgnoreAffBlob && sqlite3ExprAffinity(pColumn)==SQLITE_AFF_BLOB ){
+      break;
+    }
     /* A match is found.  Add the EP_FixedCol property */
     pConst->nChng++;
     ExprClearProperty(pExpr, EP_Leaf);
@@ -4527,6 +4539,41 @@ static int propagateConstantExprRewrite(Walker *pWalker, Expr *pExpr){
   return WRC_Prune;
 }
 
+/*
+** This is a Walker expression callback. pExpr is a node from the WHERE
+** clause of a SELECT statement. This function examines pExpr to see if
+** any substitutions based on the contents of pWalker->u.pConst should
+** be made to pExpr or its immediate children.
+**
+** A substitution is made if:
+**
+**   + pExpr is a column with an affinity other than BLOB that matches
+**     one of the columns in pWalker->u.pConst, or
+**
+**   + pExpr is a binary comparison operator (=, <=, >=, <, >) that
+**     uses an affinity other than TEXT and one of its immediate
+**     children is a column that matches one of the columns in 
+**     pWalker->u.pConst.
+*/
+static int propagateConstantExprRewrite(Walker *pWalker, Expr *pExpr){
+  WhereConst *pConst = pWalker->u.pConst;
+  if( pConst->bHasAffBlob ){
+    if( pExpr->op==TK_EQ
+     || pExpr->op==TK_LE
+     || pExpr->op==TK_GE
+     || pExpr->op==TK_LT
+     || pExpr->op==TK_GT
+     || pExpr->op==TK_IS
+    ){
+      propagateConstantExprRewriteOne(pConst, pExpr->pLeft, 0);
+      if( sqlite3ExprAffinity(pExpr->pLeft)!=SQLITE_AFF_TEXT ){
+        propagateConstantExprRewriteOne(pConst, pExpr->pRight, 0);
+      }
+    }
+  }
+  return propagateConstantExprRewriteOne(pConst, pExpr, pConst->bHasAffBlob);
+}
+
 /*
 ** The WHERE-clause constant propagation optimization.
 **
@@ -4575,6 +4622,7 @@ static int propagateConstants(
     x.nConst = 0;
     x.nChng = 0;
     x.apExpr = 0;
+    x.bHasAffBlob = 0;
     findConstInWhere(&x, p->pWhere);
     if( x.nConst ){
       memset(&w, 0, sizeof(w));