[Bugfix] get remote characteristic by uuid returning the wrong instance.

src/NimBLERemoteService.cpp

@@ -25,7 +25,6 @@
 # include "NimBLELog.h"
 
 # include <climits>
-# include <algorithm>
 
 static const char* LOG_TAG = "NimBLERemoteService";
 
@@ -77,48 +76,34 @@ NimBLERemoteCharacteristic* NimBLERemoteService::getCharacteristic(const char* u
 NimBLERemoteCharacteristic* NimBLERemoteService::getCharacteristic(const NimBLEUUID& uuid) const {
     NIMBLE_LOGD(LOG_TAG, ">> getCharacteristic: uuid: %s", uuid.toString().c_str());
     NimBLERemoteCharacteristic* pChar     = nullptr;
-    size_t                      prev_size = m_vChars.size();
 
     for (const auto& it : m_vChars) {
         if (it->getUUID() == uuid) {
             pChar = it;
-            goto Done;
+            NIMBLE_LOGD(LOG_TAG, "<< getCharacteristic: found in cache");
+            return pChar;
         }
     }
 
-    if (retrieveCharacteristics(&uuid)) {
-        if (m_vChars.size() > prev_size) {
-            pChar = m_vChars.back();
-            goto Done;
-        }
-
+    if (retrieveCharacteristics(&uuid, &pChar) && pChar == nullptr) {
         // If the request was successful but 16/32 bit uuid not found
         // try again with the 128 bit uuid.
         if (uuid.bitSize() == BLE_UUID_TYPE_16 || uuid.bitSize() == BLE_UUID_TYPE_32) {
             NimBLEUUID uuid128(uuid);
             uuid128.to128();
-            if (retrieveCharacteristics(&uuid128)) {
-                if (m_vChars.size() > prev_size) {
-                    pChar = m_vChars.back();
-                }
-            }
+            retrieveCharacteristics(&uuid128, &pChar);
         } else {
             // If the request was successful but the 128 bit uuid not found
             // try again with the 16 bit uuid.
             NimBLEUUID uuid16(uuid);
             uuid16.to16();
             // if the uuid was 128 bit but not of the BLE base type this check will fail
             if (uuid16.bitSize() == BLE_UUID_TYPE_16) {
-                if (retrieveCharacteristics(&uuid16)) {
-                    if (m_vChars.size() > prev_size) {
-                        pChar = m_vChars.back();
-                    }
-                }
+                retrieveCharacteristics(&uuid16, &pChar);
             }
         }
     }
 
-Done:
     NIMBLE_LOGD(LOG_TAG, "<< Characteristic %sfound", pChar ? "" : "not ");
     return pChar;
 } // getCharacteristic
@@ -166,7 +151,18 @@ int NimBLERemoteService::characteristicDiscCB(uint16_t              conn_handle,
     }
 
     if (error->status == 0) {
-        pSvc->m_vChars.push_back(new NimBLERemoteCharacteristic(pSvc, chr));
+        // insert in handle order
+        auto pNewChar = new NimBLERemoteCharacteristic(pSvc, chr);
+        for (auto it = pSvc->m_vChars.begin(); it != pSvc->m_vChars.end(); ++it) {
+            if ((*it)->getHandle() > chr->def_handle) {
+                pSvc->m_vChars.insert(it, pNewChar);
+                pTaskData->m_pBuf = pNewChar;
+                return 0;
+            }
+        }
+
+        pSvc->m_vChars.push_back(pNewChar);
+        pTaskData->m_pBuf = pNewChar;
         return 0;
     }
 
@@ -180,7 +176,7 @@ int NimBLERemoteService::characteristicDiscCB(uint16_t              conn_handle,
  * This function will not return until we have all the characteristics.
  * @return True if successful.
  */
-bool NimBLERemoteService::retrieveCharacteristics(const NimBLEUUID* uuidFilter) const {
+bool NimBLERemoteService::retrieveCharacteristics(const NimBLEUUID* uuidFilter, NimBLERemoteCharacteristic** ppChar) const {
     NIMBLE_LOGD(LOG_TAG, ">> retrieveCharacteristics()");
     int            rc = 0;
     NimBLETaskData taskData(const_cast<NimBLERemoteService*>(this));
@@ -208,12 +204,9 @@ bool NimBLERemoteService::retrieveCharacteristics(const NimBLEUUID* uuidFilter)
     NimBLEUtils::taskWait(taskData, BLE_NPL_TIME_FOREVER);
     rc = taskData.m_flags;
     if (rc == 0 || rc == BLE_HS_EDONE) {
-        // sort the characteristics vector by handle to make sure the search range for descriptors is correct
-        std::sort(m_vChars.begin(),
-                  m_vChars.end(),
-                  [](const NimBLERemoteCharacteristic* a, const NimBLERemoteCharacteristic* b) {
-                      return a->getHandle() < b->getHandle();
-                  });
+        if (ppChar != nullptr) {
+            *ppChar = static_cast<NimBLERemoteCharacteristic*>(taskData.m_pBuf);
+        }
         NIMBLE_LOGD(LOG_TAG, "<< retrieveCharacteristics()");
         return true;
     }

src/NimBLERemoteService.h

@@ -53,7 +53,7 @@ class NimBLERemoteService : public NimBLEAttribute {
 
     NimBLERemoteService(NimBLEClient* pClient, const struct ble_gatt_svc* service);
     ~NimBLERemoteService();
-    bool       retrieveCharacteristics(const NimBLEUUID* uuidFilter = nullptr) const;
+    bool retrieveCharacteristics(const NimBLEUUID* uuidFilter = nullptr, NimBLERemoteCharacteristic** ppChar = nullptr) const;
     static int characteristicDiscCB(uint16_t                     conn_handle,
                                     const struct ble_gatt_error* error,
                                     const struct ble_gatt_chr*   chr,