From 93acc99a148eeeac02bf78ee1aa54ab0d9feea03 Mon Sep 17 00:00:00 2001
From: Yufeng Wang <yufengwang@google.com>
Date: Tue, 29 Mar 2022 08:28:04 -0700
Subject: [PATCH] Adjust the logic to release UserLabelIterator

---
 .../user-label-server/user-label-server.cpp   | 29 +++++++++++--------
 src/include/platform/DeviceInfoProvider.h     |  4 +--
 src/platform/Linux/DeviceInfoProviderImpl.cpp |  4 +--
 src/platform/Linux/DeviceInfoProviderImpl.h   |  4 +--
 4 files changed, 23 insertions(+), 18 deletions(-)

diff --git a/src/app/clusters/user-label-server/user-label-server.cpp b/src/app/clusters/user-label-server/user-label-server.cpp
index 12b2cd880d5724..e24d19a81f57f8 100644
--- a/src/app/clusters/user-label-server/user-label-server.cpp
+++ b/src/app/clusters/user-label-server/user-label-server.cpp
@@ -61,22 +61,27 @@ CHIP_ERROR UserLabelAttrAccess::ReadLabelList(EndpointId endpoint, AttributeValu
 
     DeviceLayer::DeviceInfoProvider::UserLabelIterator * it = DeviceLayer::GetDeviceInfoProvider()->IterateUserLabel(endpoint);
 
-    if (it && it->Count() > 0)
+    if (it)
     {
-        err = aEncoder.EncodeList([&it](const auto & encoder) -> CHIP_ERROR {
-            CHIP_ERROR error = CHIP_NO_ERROR;
-            UserLabel::Structs::LabelStruct::Type userlabel;
+        if (it->Count() > 0)
+        {
+            err = aEncoder.EncodeList([&it](const auto & encoder) -> CHIP_ERROR {
+                UserLabel::Structs::LabelStruct::Type userlabel;
 
-            while (it->Next(userlabel))
-            {
-                SuccessOrExit(error = encoder.Encode(userlabel));
-            }
+                while (it->Next(userlabel))
+                {
+                    ReturnErrorOnFailure(encoder.Encode(userlabel));
+                }
 
-        exit:
-            it->Release();
+                return CHIP_NO_ERROR;
+            });
+        }
+        else
+        {
+            err = aEncoder.EncodeEmptyList();
+        }
 
-            return error;
-        });
+        it->Release();
     }
     else
     {
diff --git a/src/include/platform/DeviceInfoProvider.h b/src/include/platform/DeviceInfoProvider.h
index e4fc5135352e24..6861c2eae0c591 100644
--- a/src/include/platform/DeviceInfoProvider.h
+++ b/src/include/platform/DeviceInfoProvider.h
@@ -29,7 +29,7 @@ namespace chip {
 namespace DeviceLayer {
 
 static constexpr size_t kMaxUserLabelListLength = 10;
-static constexpr size_t kMaxLabelLength         = 16;
+static constexpr size_t kMaxLabelNameLength     = 16;
 static constexpr size_t kMaxLabelValueLength    = 16;
 
 class DeviceInfoProvider
@@ -48,7 +48,7 @@ class DeviceInfoProvider
          */
         virtual size_t Count() = 0;
         /**
-         *   @param[out] item  Value associated with the next element in the iteration.
+         *  @param[out] item  Value associated with the next element in the iteration.
          *  @retval true if the next entry is successfully retrieved.
          *  @retval false if no more entries can be found.
          */
diff --git a/src/platform/Linux/DeviceInfoProviderImpl.cpp b/src/platform/Linux/DeviceInfoProviderImpl.cpp
index 20e2968e26373f..1c5ad3e55c0fb8 100644
--- a/src/platform/Linux/DeviceInfoProviderImpl.cpp
+++ b/src/platform/Linux/DeviceInfoProviderImpl.cpp
@@ -105,10 +105,10 @@ bool DeviceInfoProviderImpl::UserLabelIteratorImpl::Next(UserLabelType & output)
 
     if (err == CHIP_NO_ERROR)
     {
-        VerifyOrReturnError(std::strlen(labelPtr) <= kMaxLabelLength, false);
+        VerifyOrReturnError(std::strlen(labelPtr) <= kMaxLabelNameLength, false);
         VerifyOrReturnError(std::strlen(valuePtr) <= kMaxLabelValueLength, false);
 
-        Platform::CopyString(mUserLabelBuf, kMaxLabelLength, labelPtr);
+        Platform::CopyString(mUserLabelBuf, kMaxLabelNameLength, labelPtr);
         Platform::CopyString(mUserValueBuf, kMaxLabelValueLength, valuePtr);
 
         output.label = CharSpan::fromCharString(mUserLabelBuf);
diff --git a/src/platform/Linux/DeviceInfoProviderImpl.h b/src/platform/Linux/DeviceInfoProviderImpl.h
index 6a279b34e6722c..8e72f0e910c668 100644
--- a/src/platform/Linux/DeviceInfoProviderImpl.h
+++ b/src/platform/Linux/DeviceInfoProviderImpl.h
@@ -46,8 +46,8 @@ class DeviceInfoProviderImpl : public DeviceInfoProvider
         EndpointId mEndpoint = 0;
         size_t mIndex        = 0;
         size_t mTotal        = 0;
-        char mUserLabelBuf[kMaxLabelLength];
-        char mUserValueBuf[kMaxLabelValueLength];
+        char mUserLabelBuf[kMaxLabelNameLength + 1];
+        char mUserValueBuf[kMaxLabelValueLength + 1];
     };
 
     CHIP_ERROR SetUserLabelCount(EndpointId endpoint, size_t val) override;