From d34143ecf811dcf64c273300a493a004c9e41de5 Mon Sep 17 00:00:00 2001
From: Viacheslav Gonkivskyi <viacheslavgonkivskyi@gmail.com>
Date: Mon, 9 Oct 2023 16:57:24 +0300
Subject: [PATCH] fix(blob/service): fix getByCommitment

---
 blob/service.go                | 102 ++++++++++++++++++++-------------
 nodebuilder/tests/blob_test.go |   3 +-
 2 files changed, 63 insertions(+), 42 deletions(-)

diff --git a/blob/service.go b/blob/service.go
index 2130904aa7..0257b0e146 100644
--- a/blob/service.go
+++ b/blob/service.go
@@ -212,16 +212,41 @@ func (s *Service) getByCommitment(
 		return nil, nil, err
 	}
 	for _, row := range namespacedShares {
-		if len(row.Shares) == 0 {
-			break
-		}
-
 		rawShares = append(rawShares, row.Shares...)
 		proofs = append(proofs, row.Proof)
 
-		// reconstruct the `blobShare` from the first rawShare in range
-		// in order to get blob's length(first share will contain this info)
-		if blobShare == nil {
+		if blobShare != nil {
+			// move to the next row if the blob is incomplete.
+			if amount > len(rawShares) {
+				continue
+			}
+
+			blob, same, err := constructAndVerifyBlob(rawShares[:amount], commitment)
+			if err != nil {
+				return nil, nil, err
+			}
+			if same {
+				return blob, &proofs, nil
+			}
+
+			// drop info of the checked blob
+			if amount == len(rawShares) {
+				rawShares = nil
+				proofs = nil
+			} else {
+				rawShares = rawShares[amount:]
+				// save proof for the last row in case we have rawShares
+				proofs = proofs[len(proofs)-1:]
+			}
+			blobShare = nil
+			amount = 0
+		}
+
+		// iterate until we will check every blob from the current row(that is not expanded to
+		// the next row)
+		for {
+			// reconstruct the `blobShare` from the first rawShare in range
+			// in order to get blob's length(first share will contain this info)
 			for i, shr := range rawShares {
 				bShare, err := shares.NewShare(shr)
 				if err != nil {
@@ -249,45 +274,40 @@ func (s *Service) getByCommitment(
 				rawShares = rawShares[i:]
 				break
 			}
-		}
-
-		// move to the next row if the blob is incomplete.
-		if amount > len(rawShares) {
-			continue
-		}
 
-		blob, same, err := constructAndVerifyBlob(rawShares[:amount], commitment)
-		if err != nil {
-			return nil, nil, err
-		}
-		if same {
-			return blob, &proofs, nil
-		}
+			if blobShare == nil {
+				// clear rawShares in case if we could not find any non-padding share
+				rawShares = nil
+				// clear proofs because we are moving to the next row without extra shares
+				proofs = nil
+				break
+			}
 
-		// drop info of the checked blob
-		rawShares = rawShares[amount:]
-		if len(rawShares) > 0 {
-			// save proof for the last row in case we have rawShares
-			proofs = proofs[len(proofs)-1:]
-		} else {
-			// otherwise clear proofs
-			proofs = nil
-		}
-		blobShare = nil
-	}
+			// move to the next row if the blob is incomplete.
+			if amount > len(rawShares) {
+				break
+			}
 
-	if len(rawShares) == 0 {
-		return nil, nil, ErrBlobNotFound
-	}
+			blob, same, err := constructAndVerifyBlob(rawShares[:amount], commitment)
+			if err != nil {
+				return nil, nil, err
+			}
+			if same {
+				return blob, &proofs, nil
+			}
 
-	blob, same, err := constructAndVerifyBlob(rawShares, commitment)
-	if err != nil {
-		return nil, nil, err
-	}
-	if same {
-		return blob, &proofs, nil
+			// drop info of the checked blob
+			if amount == len(rawShares) {
+				rawShares = nil
+				proofs = nil
+				break
+			} else {
+				rawShares = rawShares[amount:]
+			}
+			blobShare = nil
+			amount = 0
+		}
 	}
-
 	return nil, nil, ErrBlobNotFound
 }
 
diff --git a/nodebuilder/tests/blob_test.go b/nodebuilder/tests/blob_test.go
index 2078fbfa74..852ca29c88 100644
--- a/nodebuilder/tests/blob_test.go
+++ b/nodebuilder/tests/blob_test.go
@@ -3,6 +3,7 @@ package tests
 import (
 	"bytes"
 	"context"
+	"strings"
 	"testing"
 	"time"
 
@@ -120,7 +121,7 @@ func TestBlobModule(t *testing.T) {
 				b, err := fullClient.Blob.Get(ctx, height, newBlob.Namespace(), newBlob.Commitment)
 				assert.Nil(t, b)
 				require.Error(t, err)
-				require.ErrorIs(t, err, blob.ErrBlobNotFound)
+				require.True(t, strings.Contains(err.Error(), blob.ErrBlobNotFound.Error()))
 			},
 		},
 	}