Mark whether a PID is present in response.

2 files changed, 8 insertions, 4 deletions

diff --git a/src/obd2/obd2.c b/src/obd2/obd2.c
index 5b282f16..5061dd6b 100644
--- a/src/obd2/obd2.c
+++ b/src/obd2/obd2.c
@@ -154,9 +154,9 @@ static bool handle_positive_response(DiagnosticRequestHandle* handle,
         // hide the "response" version of the mode from the user
         // if it matched
         response->mode = handle->request.mode;
-        bool has_pid = false;
+        response->has_pid = false;
         if(handle->request.pid_length > 0 && message->size > 1) {
-            has_pid = true;
+            response->has_pid = true;
             if(handle->request.pid_length == 2) {
                 response->pid = get_bitfield(message->payload, message->size,
                         PID_BYTE_INDEX * CHAR_BIT, sizeof(uint16_t) * CHAR_BIT);
@@ -173,7 +173,7 @@ static bool handle_positive_response(DiagnosticRequestHandle* handle,
                     response->payload_length);
         }
 
-        if((handle->request.pid_length == 0 && !has_pid)
+        if((handle->request.pid_length == 0 && !response->has_pid)
                 || response->pid == handle->request.pid) {
             response->success = true;
             response->completed = true;
diff --git a/src/obd2/obd2_types.h b/src/obd2/obd2_types.h
index 0699fc4b..15552e88 100644
--- a/src/obd2/obd2_types.h
+++ b/src/obd2/obd2_types.h
@@ -83,7 +83,10 @@ typedef enum {
  *      the negative_response_code field for the reason.
  * arbitration_id - The arbitration ID the response was received on.
  * mode - The OBD-II mode for the original request.
- * pid - If the request was for a PID, this is the PID echo.
+ * has_pid - If this is a response to a PID request, this will be true and the
+ *      'pid' field will be valid.
+ * pid - If the request was for a PID, this is the PID echo. Only valid if
+ *      'has_pid' is true.
  * negative_response_code - If the request was not successful, 'success' will be
  *      false and this will be set to a DiagnosticNegativeResponseCode returned
  *      by the other node.
@@ -95,6 +98,7 @@ typedef struct {
     bool success;
     uint16_t arbitration_id;
     uint8_t mode;
+    bool has_pid;
     uint16_t pid;
     DiagnosticNegativeResponseCode negative_response_code;
     uint8_t payload[MAX_OBD2_PAYLOAD_LENGTH];