Improve implementation of EEOP_BOOLTEST_* opcodes.

Both Andres and I were happy with "*op->resvalue = *op->resvalue;",
but Coverity isn't; and it has a point, because some compilers might
not be smart enough to elide that.  So remove it.  In passing, also
avoid doing unnecessary assignments to *op->resnull when it's already
known to have the right value.

diff --git a/src/backend/executor/execExprInterp.c b/src/backend/executor/execExprInterp.c
index de7fe895f8153d3270041647fe84d6708f234022..02fb29cde3fd332e6a3c7bf59934652b0a18927c 100644 (file)
--- a/src/backend/executor/execExprInterp.c
+++ b/src/backend/executor/execExprInterp.c
@@ -958,10 +958,11 @@ ExecInterpExpr(ExprState *state, ExprContext *econtext, bool *isnull)
        EEO_CASE(EEOP_BOOLTEST_IS_TRUE)
        {
            if (*op->resnull)
+           {
                *op->resvalue = BoolGetDatum(false);
-           else
-               *op->resvalue = *op->resvalue;
-           *op->resnull = false;
+               *op->resnull = false;
+           }
+           /* else, input value is the correct output as well */
 
            EEO_NEXT();
        }
@@ -969,10 +970,12 @@ ExecInterpExpr(ExprState *state, ExprContext *econtext, bool *isnull)
        EEO_CASE(EEOP_BOOLTEST_IS_NOT_TRUE)
        {
            if (*op->resnull)
+           {
                *op->resvalue = BoolGetDatum(true);
+               *op->resnull = false;
+           }
            else
                *op->resvalue = BoolGetDatum(!DatumGetBool(*op->resvalue));
-           *op->resnull = false;
 
            EEO_NEXT();
        }
@@ -980,10 +983,12 @@ ExecInterpExpr(ExprState *state, ExprContext *econtext, bool *isnull)
        EEO_CASE(EEOP_BOOLTEST_IS_FALSE)
        {
            if (*op->resnull)
+           {
                *op->resvalue = BoolGetDatum(false);
+               *op->resnull = false;
+           }
            else
                *op->resvalue = BoolGetDatum(!DatumGetBool(*op->resvalue));
-           *op->resnull = false;
 
            EEO_NEXT();
        }
@@ -991,10 +996,11 @@ ExecInterpExpr(ExprState *state, ExprContext *econtext, bool *isnull)
        EEO_CASE(EEOP_BOOLTEST_IS_NOT_FALSE)
        {
            if (*op->resnull)
+           {
                *op->resvalue = BoolGetDatum(true);
-           else
-               *op->resvalue = *op->resvalue;
-           *op->resnull = false;
+               *op->resnull = false;
+           }
+           /* else, input value is the correct output as well */
 
            EEO_NEXT();
        }