Improve error message for connection failures

Previous ApiException message would simply print out the result of the
`curl_getinfo($curl)` call, which might be useful only if the developer
actually wanted very low-level information from curl about why a call
failed. The new message should print out a higher-level but more
informative, human-readable message. If necessary for debugging, the
ApiException's responseObject is set to the `curl_getinfo($curl)`.

modules/swagger-codegen/src/main/resources/php/ApiClient.mustache

@@ -224,7 +224,19 @@ class ApiClient
 
         // Handle the response
         if ($response_info['http_code'] == 0) {
-            throw new ApiException("API call to $url timed out: ".serialize($response_info), 0, null, null);
+            $curl_error_message = curl_error($curl);
+
+            // curl_exec can sometimes fail but still return a blank message from curl_error().
+            if (!empty($curl_error_message)) {
+                $error_message = "API call to $url failed: $curl_error_message";
+            } else {
+                $error_message = "API call to $url failed, but for an unknown reason. " .
+                    "This could happen if you are disconnected from the network.";
+            }
+
+            $exception = new ApiException($error_message, 0, null, null);
+            $exception->setResponseObject($response_info);
+            throw $exception;
         } elseif ($response_info['http_code'] >= 200 && $response_info['http_code'] <= 299) {
             // return raw body if response is a file
             if ($responseType == '\SplFileObject' || $responseType == 'string') {

samples/client/petstore-security-test/php/SwaggerClient-php/README.md

@@ -4,7 +4,7 @@ This spec is mainly for testing Petstore server and contains fake endpoints, mod
 This PHP package is automatically generated by the [Swagger Codegen](https://github.com/swagger-api/swagger-codegen) project:
 
 - API version: 1.0.0 */ ' " =end
-- Build date: 2016-07-06T12:08:58.407-07:00
+- Build date: 2016-07-06T12:09:22.895-07:00
 - Build package: class io.swagger.codegen.languages.PhpClientCodegen
 
 ## Requirements

samples/client/petstore-security-test/php/SwaggerClient-php/lib/ApiClient.php

@@ -245,7 +245,19 @@ class ApiClient
 
         // Handle the response
         if ($response_info['http_code'] == 0) {
-            throw new ApiException("API call to $url timed out: ".serialize($response_info), 0, null, null);
+            $curl_error_message = curl_error($curl);
+
+            // curl_exec can sometimes fail but still return a blank message from curl_error().
+            if (!empty($curl_error_message)) {
+                $error_message = "API call to $url failed: $curl_error_message";
+            } else {
+                $error_message = "API call to $url failed, but for an unknown reason. " .
+                    "This could happen if you are disconnected from the network.";
+            }
+
+            $exception = new ApiException($error_message, 0, null, null);
+            $exception->setResponseObject($response_info);
+            throw $exception;
         } elseif ($response_info['http_code'] >= 200 && $response_info['http_code'] <= 299) {
             // return raw body if response is a file
             if ($responseType == '\SplFileObject' || $responseType == 'string') {

samples/client/petstore/php/SwaggerClient-php/README.md

@@ -4,7 +4,7 @@ This spec is mainly for testing Petstore server and contains fake endpoints, mod
 This PHP package is automatically generated by the [Swagger Codegen](https://github.com/swagger-api/swagger-codegen) project:
 
 - API version: 1.0.0
-- Build date: 2016-07-06T12:01:52.156-07:00
+- Build date: 2016-07-06T12:05:01.729-07:00
 - Build package: class io.swagger.codegen.languages.PhpClientCodegen
 
 ## Requirements

samples/client/petstore/php/SwaggerClient-php/lib/ApiClient.php

@@ -245,7 +245,19 @@ class ApiClient
 
         // Handle the response
         if ($response_info['http_code'] == 0) {
-            throw new ApiException("API call to $url timed out: ".serialize($response_info), 0, null, null);
+            $curl_error_message = curl_error($curl);
+
+            // curl_exec can sometimes fail but still return a blank message from curl_error().
+            if (!empty($curl_error_message)) {
+                $error_message = "API call to $url failed: $curl_error_message";
+            } else {
+                $error_message = "API call to $url failed, but for an unknown reason. " .
+                    "This could happen if you are disconnected from the network.";
+            }
+
+            $exception = new ApiException($error_message, 0, null, null);
+            $exception->setResponseObject($response_info);
+            throw $exception;
         } elseif ($response_info['http_code'] >= 200 && $response_info['http_code'] <= 299) {
             // return raw body if response is a file
             if ($responseType == '\SplFileObject' || $responseType == 'string') {