From 76c33da3ee407a5e83125627c6ff916432aeda15 Mon Sep 17 00:00:00 2001
From: vkd <vkd.castle@gmail.com>
Date: Thu, 8 Sep 2016 16:07:49 +0300
Subject: [PATCH 1/2] fix iterator across empty pages

---
 iterator.go      | 39 ++++++++++++++++++++++-----------------
 iterator_test.go | 23 +++++++++++++++++++++++
 2 files changed, 45 insertions(+), 17 deletions(-)

diff --git a/iterator.go b/iterator.go
index 0a3df063..e8872fb3 100644
--- a/iterator.go
+++ b/iterator.go
@@ -46,25 +46,30 @@ func (it *ScanIterator) Next() bool {
 		return true
 	}
 
-	// Return if there is more data to fetch.
-	if it.ScanCmd.cursor == 0 {
-		return false
-	}
+	for {
+		// Return if there is more data to fetch.
+		if it.ScanCmd.cursor == 0 {
+			return false
+		}
 
-	// Fetch next page.
-	if it.ScanCmd._args[0] == "scan" {
-		it.ScanCmd._args[1] = it.ScanCmd.cursor
-	} else {
-		it.ScanCmd._args[2] = it.ScanCmd.cursor
-	}
-	it.ScanCmd.reset()
-	it.client.process(it.ScanCmd)
-	if it.ScanCmd.Err() != nil {
-		return false
-	}
+		// Fetch next page.
+		if it.ScanCmd._args[0] == "scan" {
+			it.ScanCmd._args[1] = it.ScanCmd.cursor
+		} else {
+			it.ScanCmd._args[2] = it.ScanCmd.cursor
+		}
+		it.ScanCmd.reset()
+		it.client.process(it.ScanCmd)
+		if it.ScanCmd.Err() != nil {
+			return false
+		}
 
-	it.pos = 1
-	return len(it.ScanCmd.page) > 0
+		it.pos = 1
+		if len(it.ScanCmd.page) > 0 {
+			return true
+		}
+	}
+	return false
 }
 
 // Val returns the key/field at the current cursor position.
diff --git a/iterator_test.go b/iterator_test.go
index f752f68c..7b301768 100644
--- a/iterator_test.go
+++ b/iterator_test.go
@@ -21,6 +21,18 @@ var _ = Describe("ScanIterator", func() {
 		return err
 	}
 
+	var extraSeed = func(n int, m int) error {
+		pipe := client.Pipeline()
+		for i := 1; i <= m; i++ {
+			pipe.Set(fmt.Sprintf("A%02d", i), "x", 0).Err()
+		}
+		for i := 1; i <= n; i++ {
+			pipe.Set(fmt.Sprintf("K%02d", i), "x", 0).Err()
+		}
+		_, err := pipe.Exec()
+		return err
+	}
+
 	var hashKey = "K_HASHTEST"
 	var hashSeed = func(n int) error {
 		pipe := client.Pipeline()
@@ -110,4 +122,15 @@ var _ = Describe("ScanIterator", func() {
 		Expect(vals).To(HaveLen(13))
 	})
 
+	It("should scan with match across empty pages", func() {
+		Expect(extraSeed(2, 10)).NotTo(HaveOccurred())
+
+		var vals []string
+		iter := client.Scan(0, "K*", 1).Iterator()
+		for iter.Next() {
+			vals = append(vals, iter.Val())
+		}
+		Expect(iter.Err()).NotTo(HaveOccurred())
+		Expect(vals).To(HaveLen(2))
+	})
 })

From cbf8ff22f55038e0681e43be48c01b37847b507c Mon Sep 17 00:00:00 2001
From: vkd <vkd.castle@gmail.com>
Date: Thu, 8 Sep 2016 16:40:45 +0300
Subject: [PATCH 2/2] fix comments

---
 iterator.go | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/iterator.go b/iterator.go
index e8872fb3..d48ad7b8 100644
--- a/iterator.go
+++ b/iterator.go
@@ -47,7 +47,7 @@ func (it *ScanIterator) Next() bool {
 	}
 
 	for {
-		// Return if there is more data to fetch.
+		// Return if there is no more data to fetch.
 		if it.ScanCmd.cursor == 0 {
 			return false
 		}
@@ -65,6 +65,8 @@ func (it *ScanIterator) Next() bool {
 		}
 
 		it.pos = 1
+
+		// Redis can occasionally return empty page
 		if len(it.ScanCmd.page) > 0 {
 			return true
 		}