Update the RetryPolicy and ShouldRetry customization logic to allow loosening the retry condition.

sdk/core/azure-core/CHANGELOG.md

@@ -13,6 +13,7 @@
 ### Other Changes
 
 - [[#5622]](https://github.com/Azure/azure-sdk-for-cpp/pull/5622) Documentation fix for building the SDK with specific OpenSSL version.  (A community contribution, courtesy of _[ByteYue](https://github.com/ByteYue)_)
+- [[#5515]](https://github.com/Azure/azure-sdk-for-cpp/issues/5515) Add a `ShouldRetry` virtual method to the retry policy to enable customization of service-specific retry logic.
 
 ### Acknowledgments
 

sdk/core/azure-core/inc/azure/core/http/policies/policy.hpp

@@ -420,7 +420,7 @@ namespace Azure { namespace Core { namespace Http { namespace Policies {
        * request. Custom implementations of this method that override the retry behavior, should
        * handle that error case, if that needs to be customized.
        *
-       * @remark Unless overriden, the default implementation is to always return true. The
+       * @remark Unless overriden, the default implementation is to always return `false`. The
        * non-retriable errors, including those specified in the RetryOptions, remain evaluated
        * before calling ShouldRetry.
        *

sdk/core/azure-core/src/http/retry_policy.cpp

@@ -120,7 +120,7 @@ int32_t RetryPolicy::GetRetryCount(Context const& context)
 
 bool RetryPolicy::ShouldRetry(std::unique_ptr<RawResponse> const&, RetryOptions const&) const
 {
-  return true;
+  return false;
 }
 
 std::unique_ptr<RawResponse> RetryPolicy::Send(
@@ -147,17 +147,14 @@ std::unique_ptr<RawResponse> RetryPolicy::Send(
 
       // If we are out of retry attempts, if a response is non-retriable (or simply 200 OK, i.e
       // doesn't need to be retried), then ShouldRetryOnResponse returns false.
-      if (!ShouldRetryOnResponse(*response.get(), m_retryOptions, attempt, retryAfter))
-      {
-        // If this is the second attempt and StartTry was called, we need to stop it. Otherwise
-        // trying to perform same request would use last retry query/headers
-        return response;
-      }
 
       // Service SDKs can inject custom logic to define whether the request should be retried,
-      // based on the response. The default is true.
-      if (!ShouldRetry(response, m_retryOptions))
+      // based on the response. The default of `ShouldRetry` is false.
+      if (!ShouldRetryOnResponse(*response.get(), m_retryOptions, attempt, retryAfter)
+          && !ShouldRetry(response, m_retryOptions))
       {
+        // If this is the second attempt and StartTry was called, we need to stop it. Otherwise
+        // trying to perform same request would use last retry query/headers
         return response;
       }
     }