Address PR #1405 review: use parse with exceptions disabled

Replace double-parsing approach (accept() then parse()) with single
parse() call using allow_exceptions=false and is_discarded() check.
This eliminates redundant parsing and removes the need for try/catch.

Addresses review comments from lalitb and ThomsonTan.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

Author: 2 people

lib/http/HttpResponseDecoder.cpp

@@ -169,19 +169,26 @@ namespace MAT_NS_BEGIN {
     {
 #ifdef HAVE_MAT_JSONHPP
         // TODO: [MG] - parse HTTP response without json.hpp library
-        nlohmann::json responseBody;
-        try
+        std::string body(response.GetBody().begin(), response.GetBody().end());
+
+        // Handle empty body
+        if (body.empty())
         {
-            std::string body(response.GetBody().begin(), response.GetBody().end());
+            LOG_ERROR("HTTP response: body is empty, skipping processing");
+            return;
+        }
 
-            // Validate that the body is valid JSON before attempting to parse
-            if (body.empty() || !nlohmann::json::accept(body))
-            {
-                LOG_ERROR("HTTP response: body is not valid JSON, skipping processing");
-                return;
-            }
+        // Parse JSON with exceptions disabled
+        nlohmann::json responseBody = nlohmann::json::parse(body, nullptr, false);
+
+        // Check if parsing failed (returns discarded value for invalid JSON)
+        if (responseBody.is_discarded())
+        {
+            LOG_ERROR("HTTP response: body is not valid JSON, skipping processing");
+            return;
+        }
 
-            responseBody = nlohmann::json::parse(body.c_str());
+        {
             int accepted = 0;
             auto acc = responseBody.find("acc");
             if (responseBody.end() != acc)
@@ -240,10 +247,6 @@ namespace MAT_NS_BEGIN {
                 LOG_TRACE("HTTP response: all rejected");
             }
         }
-        catch (...)
-        {
-            LOG_ERROR("HTTP response: JSON parsing failed");
-        }
 #else
         UNREFERENCED_PARAMETER(response);
         UNREFERENCED_PARAMETER(result);