From: drh <>
Date: Wed, 24 Sep 2025 14:43:42 +0000 (+0000)
Subject: Fixes to short-circuit AND/OR evaluation.
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=1f030eac9fead7457f09a284da1a708cedbbf1bc;p=thirdparty%2Fsqlite.git

Fixes to short-circuit AND/OR evaluation.

FossilOrigin-Name: bc4cadbd60b97d000d2e8be843acab9d82ddf10a8125fd9cc0ae101bb9850091
---

diff --git a/manifest b/manifest
index 96072f4155..e0c48d5669 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Factor\sout\sthe\scode\sthat\shandles\sAND\sand\sOR\sshort-circuiting\sinto\sa\nseparate\ssubroutine,\sfor\sperformance\sand\slegibility.
-D 2025-09-24T13:10:55.288
+C Fixes\sto\sshort-circuit\sAND/OR\sevaluation.
+D 2025-09-24T14:43:42.310
 F .fossil-settings/binary-glob 61195414528fb3ea9693577e1980230d78a1f8b0a54c78cf1b9b24d0a409ed6a x
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
@@ -693,7 +693,7 @@ F src/date.c b6f92001f4b1f73f21774927488661d28f4dac9cd9701ed96486d96b44f5b058
 F src/dbpage.c 081c59d84f187aa0eb48d98faf9578a00bde360f68438d646a86b618653d2479
 F src/dbstat.c 73362c0df0f40ad5523a6f5501224959d0976757b511299bf892313e79d14f5c
 F src/delete.c 03a77ba20e54f0f42ebd8eddf15411ed6bdb06a2c472ac4b6b336521bf7cea42
-F src/expr.c 941ab6b635a7c6c30572c0223065e03ba6fbf656aa886f5b821ccf962ce95bc0
+F src/expr.c 0746e286897020cf36ccb09713f43151a5f9ce8f208f0ae3b32fe42908f096c2
 F src/fault.c 460f3e55994363812d9d60844b2a6de88826e007
 F src/fkey.c 928ed2517e8732113d2b9821aa37af639688d752f4ea9ac6e0e393d713eeb76f
 F src/func.c de47a8295503aa130baae5e6d9868ecf4f7c4dbffa65d83ad1f70bdbac0ee2d6
@@ -2175,8 +2175,8 @@ F tool/version-info.c 3b36468a90faf1bbd59c65fd0eb66522d9f941eedd364fabccd7227350
 F tool/warnings-clang.sh bbf6a1e685e534c92ec2bfba5b1745f34fb6f0bc2a362850723a9ee87c1b31a7
 F tool/warnings.sh 1ad0169b022b280bcaaf94a7fa231591be96b514230ab5c98fbf15cd7df842dd
 F tool/win/sqlite.vsix deb315d026cc8400325c5863eef847784a219a2f
-P 0d4447aa61848deecf9170afce031f7b353b91d58474f3f094ce34e46be7f99e
-R 1772208b5f6079b8843463f58173d5e0
+P cab84a65c3825c59f3a7a750f4983563ce7ad007125cbcf35c187326289fea89
+R 249976bcbb8ead84fd46ece0ea605849
 U drh
-Z 0a260950732cda975b0bb04f700f181c
+Z ac1897a73ee8a49c86d6ce76056d5c1b
 # Remove this line to create a well-formed Fossil manifest.
diff --git a/manifest.uuid b/manifest.uuid
index c8d630d5ed..53d156157c 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-cab84a65c3825c59f3a7a750f4983563ce7ad007125cbcf35c187326289fea89
+bc4cadbd60b97d000d2e8be843acab9d82ddf10a8125fd9cc0ae101bb9850091
diff --git a/src/expr.c b/src/expr.c
index 61b01c1112..c464fd851d 100644
--- a/src/expr.c
+++ b/src/expr.c
@@ -4811,21 +4811,26 @@ static int exprPartidxExprLookup(Parse *pParse, Expr *pExpr, int iTarget){
 }
 
 /*
-** This is the code to implement sqlite3ExprCodeTarget() for the
-** case of an AND or OR operator.  It is factored out for performance
-** and legibility.
+** Generate code that evaluates an AND or OR operator leaving a
+** boolean result in a register.  pExpr is the AND/OR expression.
+** Store the result in the "target" register.  Use short-circuit
+** evaluation to avoid computing both operands, if possible.
+**
+** The code generated might require the use of a temporary register.
+** If it does, then write the number of that temporary register
+** into *pTmpReg.  If not, leave *pTmpReg unchanged.
 */
 static SQLITE_NOINLINE int exprCodeTargetAndOr(
   Parse *pParse,     /* Parsing context */
   Expr *pExpr,       /* AND or OR expression to be coded */
   int target,        /* Put result in this register, guaranteed */
-  int *pTmpReg       /* Number of a temporary register */
+  int *pTmpReg       /* Write a temporary register here */
 ){
   int op;            /* The opcode.  TK_AND or TK_OR */
   int skipOp;        /* Opcode for the branch that skips one operand */
   int addrSkip;      /* Branch instruction that skips one of the operands */
-  int regSS = 0;
-  int r1, r2;        /* Registers holding left and right operands */
+  int regSS = 0;     /* Register holding computed operand when other omitted */
+  int r1, r2;        /* Registers for left and right operands, respectively */
   Expr *pAlt;        /* Alternative, simplified expression */
   Vdbe *v;           /* statement being coded */
 
@@ -4842,20 +4847,26 @@ static SQLITE_NOINLINE int exprCodeTargetAndOr(
   v = pParse->pVdbe;
   skipOp = op==TK_AND ? OP_IfNot : OP_If;
   if( exprEvalRhsFirst(pExpr) ){
+    /* Compute the right operand first.  Skip the computation of the left
+    ** operand if the right operand fully determines the result */
     r2 = regSS = sqlite3ExprCodeTarget(pParse, pExpr->pRight, target);
     addrSkip = sqlite3VdbeAddOp1(v, skipOp, r2);
     VdbeComment((v, "skip left operand"));
     VdbeCoverage(v); 
+    r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, pTmpReg);
   }else{
-    r2 = 0;
-    addrSkip = 0;
-  }
-  r1 = regSS = sqlite3ExprCodeTarget(pParse, pExpr->pLeft, target);
-  if( addrSkip==0 ){
+    /* Compute the left operand first */
+    r1 = sqlite3ExprCodeTarget(pParse, pExpr->pLeft, target);
     if( ExprHasProperty(pExpr->pRight, EP_Subquery) ){
+      /* Skip over the computation of the right operand if the right
+      ** operand is a subquery and the left operand completely determines
+      ** the result */
+      regSS = r1;
       addrSkip = sqlite3VdbeAddOp1(v, skipOp, r1);
       VdbeComment((v, "skip right operand"));
       VdbeCoverage(v);
+    }else{
+      addrSkip = regSS = 0;
     }
     r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, pTmpReg);
   }