Fix to cellular sockets clean-up introduce by heap accounting change.

Commit 3ffd36f introduced improved accounting for the sockets tests but, in so doing, it introduced a problem for cellular: uCellSockCleanup() was modified to remove the URCs, however that should _not_ be done until all sockets are closed, i.e. it should be done in uCellSockDeinit() instead (which is called by uSockCleanUp() once all sockets are closed).

Thanks to eeFLis for highlighting this.

cell/api/u_cell_sock.h

@@ -193,7 +193,7 @@ int32_t uCellSockClose(uDeviceHandle_t cellHandle,
 /** Clean-up.  This function should be called when
  * there is no socket activity, either locally or from
  * the remote host, in order to free memory occupied
- * by closed sockets.
+ * by sockets that have been closed.
  *
  * @param cellHandle  the handle of the cellular instance.
  */

cell/src/u_cell_sock.c

@@ -726,8 +726,18 @@ int32_t uCellSockInitInstance(uDeviceHandle_t cellHandle)
 // Deinitialise the cellular sockets layer.
 void uCellSockDeinit()
 {
+    uCellPrivateInstance_t *pInstance = gpUCellPrivateInstanceList;
+
     if (gInitialised) {
-        // Nothing to do; URCs are removed by clean-up function
+        while (pInstance != NULL) {
+            // Remove the URCs
+            for (size_t x = 0; x < sizeof(gUrcHandlers) /
+                 sizeof(gUrcHandlers[0]); x++) {
+                uAtClientRemoveUrcHandler(pInstance->atHandle,
+                                          gUrcHandlers[x].pPrefix);
+            }
+            pInstance = pInstance->pNext;
+        }
         gInitialised = false;
     }
 }
@@ -937,17 +947,8 @@ int32_t uCellSockClose(uDeviceHandle_t cellHandle,
 // Clean-up.
 void uCellSockCleanup(uDeviceHandle_t cellHandle)
 {
-    uCellPrivateInstance_t *pInstance;
-
-    pInstance = pUCellPrivateGetInstance(cellHandle);
-    if (pInstance != NULL) {
-        // Remove the URCs
-        for (size_t x = 0; x < sizeof(gUrcHandlers) /
-             sizeof(gUrcHandlers[0]); x++) {
-            uAtClientRemoveUrcHandler(pInstance->atHandle,
-                                      gUrcHandlers[x].pPrefix);
-        }
-    }
+    // Nothing to do: URCs are removed in uCellDeinit()
+    (void) cellHandle;
 }
 
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