1 files changed, 104 insertions, 35 deletions

diff --git a/src/expr.c b/src/expr.c
index 592e9dd25..5608128ad 100644
--- a/src/expr.c
+++ b/src/expr.c
@@ -44,49 +44,118 @@ char sqlite3TableColumnAffinity(const Table *pTab, int iCol){
 */
 char sqlite3ExprAffinity(const Expr *pExpr){
   int op;
-  while( ExprHasProperty(pExpr, EP_Skip|EP_IfNullRow) ){
-    assert( pExpr->op==TK_COLLATE
-         || pExpr->op==TK_IF_NULL_ROW
-         || (pExpr->op==TK_REGISTER && pExpr->op2==TK_IF_NULL_ROW) );
-    pExpr = pExpr->pLeft;
-    assert( pExpr!=0 );
-  }
   op = pExpr->op;
-  if( op==TK_REGISTER ) op = pExpr->op2;
-  if( op==TK_COLUMN || (op==TK_AGG_COLUMN && pExpr->y.pTab!=0) ){
-    assert( ExprUseYTab(pExpr) );
-    assert( pExpr->y.pTab!=0 );
-    return sqlite3TableColumnAffinity(pExpr->y.pTab, pExpr->iColumn);
-  }
-  if( op==TK_SELECT ){
-    assert( ExprUseXSelect(pExpr) );
-    assert( pExpr->x.pSelect!=0 );
-    assert( pExpr->x.pSelect->pEList!=0 );
-    assert( pExpr->x.pSelect->pEList->a[0].pExpr!=0 );
-    return sqlite3ExprAffinity(pExpr->x.pSelect->pEList->a[0].pExpr);
-  }
+  while( 1 /* exit-by-break */ ){
+    if( op==TK_COLUMN || (op==TK_AGG_COLUMN && pExpr->y.pTab!=0) ){
+      assert( ExprUseYTab(pExpr) );
+      assert( pExpr->y.pTab!=0 );
+      return sqlite3TableColumnAffinity(pExpr->y.pTab, pExpr->iColumn);
+    }
+    if( op==TK_SELECT ){
+      assert( ExprUseXSelect(pExpr) );
+      assert( pExpr->x.pSelect!=0 );
+      assert( pExpr->x.pSelect->pEList!=0 );
+      assert( pExpr->x.pSelect->pEList->a[0].pExpr!=0 );
+      return sqlite3ExprAffinity(pExpr->x.pSelect->pEList->a[0].pExpr);
+    }
 #ifndef SQLITE_OMIT_CAST
-  if( op==TK_CAST ){
-    assert( !ExprHasProperty(pExpr, EP_IntValue) );
-    return sqlite3AffinityType(pExpr->u.zToken, 0);
-  }
+    if( op==TK_CAST ){
+      assert( !ExprHasProperty(pExpr, EP_IntValue) );
+      return sqlite3AffinityType(pExpr->u.zToken, 0);
+    }
 #endif
-  if( op==TK_SELECT_COLUMN ){
-    assert( pExpr->pLeft!=0 && ExprUseXSelect(pExpr->pLeft) );
-    assert( pExpr->iColumn < pExpr->iTable );
-    assert( pExpr->iTable==pExpr->pLeft->x.pSelect->pEList->nExpr );
-    return sqlite3ExprAffinity(
-        pExpr->pLeft->x.pSelect->pEList->a[pExpr->iColumn].pExpr
-    );
-  }
-  if( op==TK_VECTOR ){
-    assert( ExprUseXList(pExpr) );
-    return sqlite3ExprAffinity(pExpr->x.pList->a[0].pExpr);
+    if( op==TK_SELECT_COLUMN ){
+      assert( pExpr->pLeft!=0 && ExprUseXSelect(pExpr->pLeft) );
+      assert( pExpr->iColumn < pExpr->iTable );
+      assert( pExpr->iTable==pExpr->pLeft->x.pSelect->pEList->nExpr );
+      return sqlite3ExprAffinity(
+          pExpr->pLeft->x.pSelect->pEList->a[pExpr->iColumn].pExpr
+      );
+    }
+    if( op==TK_VECTOR ){
+      assert( ExprUseXList(pExpr) );
+      return sqlite3ExprAffinity(pExpr->x.pList->a[0].pExpr);
+    }
+    if( ExprHasProperty(pExpr, EP_Skip|EP_IfNullRow) ){
+      assert( pExpr->op==TK_COLLATE
+           || pExpr->op==TK_IF_NULL_ROW
+           || (pExpr->op==TK_REGISTER && pExpr->op2==TK_IF_NULL_ROW) );
+      pExpr = pExpr->pLeft;
+      op = pExpr->op;
+      continue;
+    }
+    if( op!=TK_REGISTER || (op = pExpr->op2)==TK_REGISTER ) break;
   }
   return pExpr->affExpr;
 }
 
 /*
+** Make a guess at all the possible datatypes of the result that could
+** be returned by an expression.  Return a bitmask indicating the answer:
+**
+**     0x01         Numeric
+**     0x02         Text
+**     0x04         Blob
+**
+** If the expression must return NULL, then 0x00 is returned.
+*/
+int sqlite3ExprDataType(const Expr *pExpr){
+  while( pExpr ){
+    switch( pExpr->op ){
+      case TK_COLLATE:
+      case TK_IF_NULL_ROW:
+      case TK_UPLUS:  {
+        pExpr = pExpr->pLeft;
+        break;
+      }
+      case TK_NULL: {
+        return 0x00;
+      }
+      case TK_STRING: {
+        return 0x02;
+      }
+      case TK_BLOB: {
+        return 0x04;
+      }
+      case TK_CONCAT: {
+        return 0x06;
+      }
+      case TK_VARIABLE:
+      case TK_AGG_FUNCTION:
+      case TK_FUNCTION: {
+        return 0x07;
+      }
+      case TK_COLUMN:
+      case TK_AGG_COLUMN:
+      case TK_SELECT:
+      case TK_CAST:
+      case TK_SELECT_COLUMN:
+      case TK_VECTOR:  {
+        int aff = sqlite3ExprAffinity(pExpr);
+        if( aff>=SQLITE_AFF_NUMERIC ) return 0x05;
+        if( aff==SQLITE_AFF_TEXT )    return 0x06;
+        return 0x07;
+      }
+      case TK_CASE: {
+        int res = 0;
+        int ii;
+        ExprList *pList = pExpr->x.pList;
+        assert( ExprUseXList(pExpr) && pList!=0 );
+        assert( pList->nExpr > 0);
+        for(ii=1; ii<pList->nExpr; ii+=2){
+          res |= sqlite3ExprDataType(pList->a[ii].pExpr);
+        }
+        return res;
+      }
+      default: {
+        return 0x01;
+      }
+    } /* End of switch(op) */
+  } /* End of while(pExpr) */
+  return 0;
+}
+
+/*
 ** Set the collating sequence for expression pExpr to be the collating
 ** sequence named by pToken.   Return a pointer to a new Expr node that
 ** implements the COLLATE operator.