From dcdcf1356f449d688146f8909e5c1e472f4ef577 Mon Sep 17 00:00:00 2001
From: Jaden Weiss <jaden@jadendw.dev>
Date: Mon, 20 Jul 2020 19:58:24 -0400
Subject: [PATCH] fix oversized rangeEQ

---
 fragment.go               | 24 +++++++++++-------------
 fragment_internal_test.go | 24 ++++++++++++++++++++++++
 2 files changed, 35 insertions(+), 13 deletions(-)

diff --git a/fragment.go b/fragment.go
index 48fdff1f9..a8e5ad4fe 100644
--- a/fragment.go
+++ b/fragment.go
@@ -1230,12 +1230,18 @@ func (f *fragment) rangeEQ(bitDepth uint, predicate int64) (*Row, error) {
 	// Start with set of columns with values set.
 	b := f.row(bsiExistsBit)
 
-	// Filter to only positive/negative numbers.
 	upredicate := absInt64(predicate)
+	if uint(bits.Len64(upredicate)) > bitDepth {
+		// Predicate is out of range.
+		return NewRow(), nil
+	}
+
+	// Filter to only positive/negative numbers.
+	r := f.row(bsiSignBit)
 	if predicate < 0 {
-		b = b.Intersect(f.row(bsiSignBit)) // only negatives
+		b = b.Intersect(r) // only negatives
 	} else {
-		b = b.Difference(f.row(bsiSignBit)) // only positives
+		b = b.Difference(r) // only positives
 	}
 
 	// Filter any bits that don't match the current bit value.
@@ -1308,18 +1314,10 @@ func (f *fragment) rangeLT(bitDepth uint, predicate int64, allowEquality bool) (
 	}
 }
 
-// msb gives the 1-indexed position (counting from lsb) of the most
-// significant bit. E.G. for 1 it would return 1, for 2 2, for 3 2,
-// for 4 3, for 8 4, etc.
-func msb(x uint64) uint {
-	lz := bits.LeadingZeros64(x)
-	return 64 - uint(lz)
-}
-
 // rangeLTUnsigned returns all bits LT/LTE the predicate without considering the sign bit.
 func (f *fragment) rangeLTUnsigned(filter *Row, bitDepth uint, predicate uint64, allowEquality bool) (*Row, error) {
 	switch {
-	case msb(predicate) > bitDepth:
+	case uint(bits.Len64(predicate)) > bitDepth:
 		fallthrough
 	case predicate == (1<<bitDepth)-1 && allowEquality:
 		// This query matches all possible values.
@@ -1498,7 +1496,7 @@ func (f *fragment) rangeBetweenUnsigned(filter *Row, bitDepth uint, predicateMin
 	}
 
 	// Clear the bits we just compared.
-	equalMask := (^uint64(0)) << diffLen
+	equalMask := (^uint64(0)) << uint(diffLen)
 	predicateMin &^= equalMask
 	predicateMax &^= equalMask
 
diff --git a/fragment_internal_test.go b/fragment_internal_test.go
index f174e564d..64e3cb326 100644
--- a/fragment_internal_test.go
+++ b/fragment_internal_test.go
@@ -538,6 +538,30 @@ func TestFragment_Range(t *testing.T) {
 		}
 	})
 
+	t.Run("EQOversizeRegression", func(t *testing.T) {
+		f := mustOpenFragment("i", "f", viewStandard, 0, "")
+		defer f.Clean(t)
+
+		// Set values.
+		if _, err := f.setValue(1000, 1, 0); err != nil {
+			t.Fatal(err)
+		} else if _, err := f.setValue(2000, 1, 1); err != nil {
+			t.Fatal(err)
+		}
+
+		// Query for equality.
+		if b, err := f.rangeOp(pql.EQ, 1, 3); err != nil {
+			t.Fatal(err)
+		} else if !reflect.DeepEqual(b.Columns(), []uint64{}) {
+			t.Fatalf("unexpected columns: %+v", b.Columns())
+		}
+		if b, err := f.rangeOp(pql.EQ, 1, 4); err != nil {
+			t.Fatal(err)
+		} else if !reflect.DeepEqual(b.Columns(), []uint64{}) {
+			t.Fatalf("unexpected columns: %+v", b.Columns())
+		}
+	})
+
 	t.Run("NEQ", func(t *testing.T) {
 		f := mustOpenFragment("i", "f", viewStandard, 0, "")
 		defer f.Clean(t)