change new API function to have error return value

docs/libcurl/curl_multi_get_offt.md

@@ -21,7 +21,9 @@ curl_multi_get_offt - extract information from a multi handle
 ~~~c
 #include <curl/curl.h>
 
-curl_off_t curl_multi_get_offt(CURLM *multi, CURLMinfo_offt info);
+CURLMcode curl_multi_get_offt(CURLM *multi_handle,
+                              CURLMinfo_offt info,
+                              curl_off_t *pvalue);
 ~~~
 
 # DESCRIPTION
@@ -84,7 +86,7 @@ int main(void)
     /* add the transfer */
     curl_multi_add_handle(multi, curl);
 
-    n = curl_multi_get_offt(multi, CURLMINFO_XFERS_ADDED);
+    curl_multi_get_offt(multi, CURLMINFO_XFERS_ADDED, &n);
     /* on successful add, n is 1 */
   }
 }

include/curl/multi.h

@@ -472,11 +472,11 @@ typedef enum {
  *
  * Desc:    Retrieves a numeric value for the `CURLMINFO_*` enums.
  *
- * Returns: the curl_off_t value from a valid multi handle and
- *          supported `info` or -1.
+ * Returns: CULRM_OK or error when value could not be obtained.
  */
-CURL_EXTERN curl_off_t curl_multi_get_offt(CURLM *multi_handle,
-                                           CURLMinfo_offt info);
+CURL_EXTERN CURLMcode curl_multi_get_offt(CURLM *multi_handle,
+                                          CURLMinfo_offt info,
+                                          curl_off_t *pvalue);
 
 /*
  * Name: curl_push_callback

lib/multi.c

@@ -3735,30 +3735,40 @@ CURL **curl_multi_get_handles(CURLM *m)
   return a;
 }
 
-CURL_EXTERN curl_off_t curl_multi_get_offt(CURLM *m, CURLMinfo_offt info)
+CURLMcode curl_multi_get_offt(CURLM *m,
+                              CURLMinfo_offt info,
+                              curl_off_t *pvalue)
 {
   struct Curl_multi *multi = m;
 
   if(!GOOD_MULTI_HANDLE(multi))
-    return -1;
+    return CURLM_BAD_HANDLE;
+  if(!pvalue)
+    return CURLM_BAD_FUNCTION_ARGUMENT;
 
   switch(info) {
   case CURLMINFO_XFERS_CURRENT: {
     unsigned int n = Curl_uint_tbl_count(&multi->xfers);
     if(n && multi->admin)
       --n;
-    return (curl_off_t)n;
+    *pvalue = (curl_off_t)n;
+    return CURLM_OK;
   }
   case CURLMINFO_XFERS_RUNNING:
-    return (curl_off_t)Curl_uint_bset_count(&multi->process);
+    *pvalue = (curl_off_t)Curl_uint_bset_count(&multi->process);
+    return CURLM_OK;
   case CURLMINFO_XFERS_PENDING:
-    return (curl_off_t)Curl_uint_bset_count(&multi->pending);
+    *pvalue = (curl_off_t)Curl_uint_bset_count(&multi->pending);
+    return CURLM_OK;
   case CURLMINFO_XFERS_DONE:
-    return (curl_off_t)Curl_uint_bset_count(&multi->msgsent);
+    *pvalue = (curl_off_t)Curl_uint_bset_count(&multi->msgsent);
+    return CURLM_OK;
   case CURLMINFO_XFERS_ADDED:
-    return multi->xfers_total_ever;
+    *pvalue = multi->xfers_total_ever;
+    return CURLM_OK;
   default:
-    return -1;
+    *pvalue = -1;
+    return CURLM_UNKNOWN_OPTION;
   }
 }
 

src/tool_operate.c

@@ -1416,10 +1416,17 @@ static CURLcode add_parallel_transfers(struct GlobalConfig *global,
   CURLMcode mcode;
   bool sleeping = FALSE;
   char *errorbuf;
+  curl_off_t nxfers;
+
   *addedp = FALSE;
   *morep = FALSE;
-  if(curl_multi_get_offt(multi, CURLMINFO_XFERS_CURRENT) <
-     (curl_off_t)(global->parallel_max*2)) {
+  mcode = curl_multi_get_offt(multi, CURLMINFO_XFERS_CURRENT, &nxfers);
+  if(mcode) {
+    DEBUGASSERT(0);
+    return CURLE_UNKNOWN_OPTION;
+  }
+
+  if(nxfers < (curl_off_t)(global->parallel_max*2)) {
     bool skipped = FALSE;
     do {
       result = create_transfer(global, share, addedp, &skipped);

src/tool_progress.c

@@ -181,6 +181,8 @@ bool progress_meter(struct GlobalConfig *global,
     struct per_transfer *per;
     curl_off_t all_dlnow = 0;
     curl_off_t all_ulnow = 0;
+    curl_off_t xfers_added = 0;
+    curl_off_t xfers_running = 0;
     bool dlknown = TRUE;
     bool ulknown = TRUE;
     curl_off_t speed = 0;
@@ -270,6 +272,8 @@ bool progress_meter(struct GlobalConfig *global,
     }
     time2str(time_spent, spent);
 
+    (void)curl_multi_get_offt(multi, CURLMINFO_XFERS_ADDED, &xfers_added);
+    (void)curl_multi_get_offt(multi, CURLMINFO_XFERS_RUNNING, &xfers_running);
     fprintf(tool_stderr,
             "\r"
             "%-3s " /* percent downloaded */
@@ -288,8 +292,8 @@ bool progress_meter(struct GlobalConfig *global,
             ulpercen,  /* 3 letters */
             max5data(all_dlnow, buffer[0]),
             max5data(all_ulnow, buffer[1]),
-            curl_multi_get_offt(multi, CURLMINFO_XFERS_ADDED),
-            curl_multi_get_offt(multi, CURLMINFO_XFERS_RUNNING),
+            xfers_added,
+            xfers_running,
             time_total,
             time_spent,
             time_left,