From 11e2ebdfab6295dcaeaa8c7788a5107493ed90be Mon Sep 17 00:00:00 2001
From: Jose Hugo De la cruz Romero <jhugodc@gmail.com>
Date: Tue, 20 Apr 2021 10:49:59 -0600
Subject: [PATCH 1/5] Ignore PUSH data bytes, detect and ignore metadata
 corresponding to the contract swarm address

---
 codetrie/codetrie.go | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/codetrie/codetrie.go b/codetrie/codetrie.go
index 293d2fbbb4f3..fd5a2cbb809f 100644
--- a/codetrie/codetrie.go
+++ b/codetrie/codetrie.go
@@ -20,6 +20,7 @@ var (
 	versionValue  = []byte{0x00}
 	codeLengthKey = []byte{0xff, 0xfe}
 	codeHashKey   = []byte{0xff, 0xff}
+	swarmIdent    = []byte{0xa1, 0x65, 0x62, 0x7a, 0x7a, 0x72, 0x30} // a165 bzzr0
 )
 
 type Trie interface {
@@ -217,19 +218,46 @@ func setFIO(chunks []*Chunk) {
 	}
 
 	chunkSize := len(chunks[0].code)
+	swarmMatch := 0
+	swarmLeft := 0
 
 	for i, chunk := range chunks {
 		if i == len(chunks)-1 {
 			break
 		}
 
+		pushDataLeft := 0
 		for j, op := range chunk.code {
+
+			if swarmLeft > 0 {
+				swarmLeft -= 1 // skip bytes corresponding to swarm metadata
+				continue
+			}
+
+			if op == swarmIdent[swarmMatch] {
+				swarmMatch += 1
+				if swarmMatch == len(swarmIdent) {
+					swarmLeft = 36
+				}
+			} else {
+				swarmMatch = 0
+			}
+
+			if uint8(j) < chunk.fio { // FIO already set in previous chunk analysis
+				continue
+			}
+			if pushDataLeft > 0 { // current byte corresponds to PUSH data
+				pushDataLeft -= 1
+				continue
+			}
+
 			opcode := OpCode(op)
 			// Push is the only opcode with immediate
 			if !opcode.IsPush() {
 				continue
 			}
 			size := getPushSize(opcode)
+			pushDataLeft = size
 			// Fits within chunk
 			if j+size < chunkSize {
 				continue

From 7896c66e977e48dacbd05b9b67ef25e2a0a6efc3 Mon Sep 17 00:00:00 2001
From: Jose Hugo De la cruz Romero <jhugodc@gmail.com>
Date: Tue, 20 Apr 2021 21:19:01 -0600
Subject: [PATCH 2/5] fix, reset swarmMatch to 0

---
 codetrie/codetrie.go | 1 +
 1 file changed, 1 insertion(+)

diff --git a/codetrie/codetrie.go b/codetrie/codetrie.go
index fd5a2cbb809f..8c63236a5aab 100644
--- a/codetrie/codetrie.go
+++ b/codetrie/codetrie.go
@@ -238,6 +238,7 @@ func setFIO(chunks []*Chunk) {
 				swarmMatch += 1
 				if swarmMatch == len(swarmIdent) {
 					swarmLeft = 36
+					swarmMatch = 0
 				}
 			} else {
 				swarmMatch = 0

From 903dd76dee3071061734f1b4d466f40d7ac69798 Mon Sep 17 00:00:00 2001
From: Jose Hugo De la cruz Romero <jhugodc@gmail.com>
Date: Wed, 21 Apr 2021 17:03:33 -0600
Subject: [PATCH 3/5] Validate swarm metadata starting with 0xa2

---
 codetrie/codetrie.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/codetrie/codetrie.go b/codetrie/codetrie.go
index 8c63236a5aab..3fe0b798c741 100644
--- a/codetrie/codetrie.go
+++ b/codetrie/codetrie.go
@@ -234,7 +234,7 @@ func setFIO(chunks []*Chunk) {
 				continue
 			}
 
-			if op == swarmIdent[swarmMatch] {
+			if op == swarmIdent[swarmMatch] || (swarmMatch == 0 && op == 0xa2) {
 				swarmMatch += 1
 				if swarmMatch == len(swarmIdent) {
 					swarmLeft = 36

From d3c7b7e43ad586046c95a32d66f88c4661a47b02 Mon Sep 17 00:00:00 2001
From: Jose Hugo De la cruz Romero <jhugodc@gmail.com>
Date: Thu, 22 Apr 2021 12:07:43 -0600
Subject: [PATCH 4/5] Ingnore the rest of the metadata

---
 codetrie/codetrie.go | 10 ++--------
 1 file changed, 2 insertions(+), 8 deletions(-)

diff --git a/codetrie/codetrie.go b/codetrie/codetrie.go
index 3fe0b798c741..0e0571651d9f 100644
--- a/codetrie/codetrie.go
+++ b/codetrie/codetrie.go
@@ -219,7 +219,6 @@ func setFIO(chunks []*Chunk) {
 
 	chunkSize := len(chunks[0].code)
 	swarmMatch := 0
-	swarmLeft := 0
 
 	for i, chunk := range chunks {
 		if i == len(chunks)-1 {
@@ -229,17 +228,12 @@ func setFIO(chunks []*Chunk) {
 		pushDataLeft := 0
 		for j, op := range chunk.code {
 
-			if swarmLeft > 0 {
-				swarmLeft -= 1 // skip bytes corresponding to swarm metadata
-				continue
+			if swarmMatch == len(swarmIdent) {
+				continue // skip bytes corresponding to swarm metadata
 			}
 
 			if op == swarmIdent[swarmMatch] || (swarmMatch == 0 && op == 0xa2) {
 				swarmMatch += 1
-				if swarmMatch == len(swarmIdent) {
-					swarmLeft = 36
-					swarmMatch = 0
-				}
 			} else {
 				swarmMatch = 0
 			}

From f1fcb259a06eb2f5309b758e82830c086fdb08fc Mon Sep 17 00:00:00 2001
From: Jose Hugo De la cruz Romero <jhugodc@gmail.com>
Date: Thu, 22 Apr 2021 14:05:06 -0600
Subject: [PATCH 5/5] Different bzzr versions

---
 codetrie/codetrie.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/codetrie/codetrie.go b/codetrie/codetrie.go
index 0e0571651d9f..30382f1593df 100644
--- a/codetrie/codetrie.go
+++ b/codetrie/codetrie.go
@@ -20,7 +20,7 @@ var (
 	versionValue  = []byte{0x00}
 	codeLengthKey = []byte{0xff, 0xfe}
 	codeHashKey   = []byte{0xff, 0xff}
-	swarmIdent    = []byte{0xa1, 0x65, 0x62, 0x7a, 0x7a, 0x72, 0x30} // a165 bzzr0
+	swarmIdent    = []byte{0xa1, 0x65, 0x62, 0x7a, 0x7a, 0x72} // a165 bzzr
 )
 
 type Trie interface {