tool_operate: a failed etag save now only fails that transfer

When failing to create the output file for saving an etag, only fail
that particular single transfer and allow others to follow.

In a serial transfer setup, if no transfer at all is done due to them
all being skipped because of this error, curl will output an error
message and return exit code 26.

Added test 369 and 370 to verify.

Reported-by: Earnestly on github
Ref: #7942
Closes #7945

1 files changed, 77 insertions, 69 deletions

diff --git a/src/tool_operate.c b/src/tool_operate.c
index 5d24ccb7d..1a1dc6468 100644
--- a/src/tool_operate.c
+++ b/src/tool_operate.c
@@ -800,65 +800,13 @@ static CURLcode single_transfer(struct GlobalConfig *global,
         struct OutStruct *heads;
         struct OutStruct *etag_save;
         struct HdrCbData *hdrcbdata = NULL;
-        CURL *curl = curl_easy_init();
-        result = add_per_transfer(&per);
-        if(result || !curl) {
-          curl_easy_cleanup(curl);
-          result = CURLE_OUT_OF_MEMORY;
-          break;
-        }
-        if(state->uploadfile) {
-          per->uploadfile = strdup(state->uploadfile);
-          if(!per->uploadfile) {
-            curl_easy_cleanup(curl);
-            result = CURLE_OUT_OF_MEMORY;
-            break;
-          }
-        }
-        *added = TRUE;
-        per->config = config;
-        per->curl = curl;
-        per->urlnum = urlnode->num;
-
-        /* default headers output stream is stdout */
-        heads = &per->heads;
-        heads->stream = stdout;
+        struct OutStruct etag_first;
+        CURL *curl;
 
-        /* Single header file for all URLs */
-        if(config->headerfile) {
-          /* open file for output: */
-          if(strcmp(config->headerfile, "-")) {
-            FILE *newfile;
-            newfile = fopen(config->headerfile, per->prev == NULL?"wb":"ab");
-            if(!newfile) {
-              warnf(global, "Failed to open %s\n", config->headerfile);
-              result = CURLE_WRITE_ERROR;
-              break;
-            }
-            else {
-              heads->filename = config->headerfile;
-              heads->s_isreg = TRUE;
-              heads->fopened = TRUE;
-              heads->stream = newfile;
-            }
-          }
-          else {
-            /* always use binary mode for protocol header output */
-            set_binmode(heads->stream);
-          }
-        }
-
-        hdrcbdata = &per->hdrcbdata;
-
-        outs = &per->outs;
-        input = &per->input;
-
-        per->outfile = NULL;
-        per->infdopen = FALSE;
-        per->infd = STDIN_FILENO;
-
-        /* default output stream is stdout */
-        outs->stream = stdout;
+        /* --etag-save */
+        memset(&etag_first, 0, sizeof(etag_first));
+        etag_save = &etag_first;
+        etag_save->stream = stdout;
 
         /* --etag-compare */
         if(config->etag_compare_file) {
@@ -901,21 +849,16 @@ static CURLcode single_transfer(struct GlobalConfig *global,
           }
         }
 
-        /* --etag-save */
-        etag_save = &per->etag_save;
-        etag_save->stream = stdout;
-
         if(config->etag_save_file) {
           /* open file for output: */
           if(strcmp(config->etag_save_file, "-")) {
             FILE *newfile = fopen(config->etag_save_file, "wb");
             if(!newfile) {
-              warnf(
-                global,
-                "Failed to open %s\n", config->etag_save_file);
-
-              result = CURLE_WRITE_ERROR;
-              break;
+              warnf(global, "Failed creating file for saving etags: \"%s\". "
+                    "Skip this transfer\n", config->etag_save_file);
+              Curl_safefree(state->outfiles);
+              glob_cleanup(state->urls);
+              return CURLE_OK;
             }
             else {
               etag_save->filename = config->etag_save_file;
@@ -930,6 +873,67 @@ static CURLcode single_transfer(struct GlobalConfig *global,
           }
         }
 
+        curl = curl_easy_init();
+        result = add_per_transfer(&per);
+        if(result || !curl) {
+          curl_easy_cleanup(curl);
+          result = CURLE_OUT_OF_MEMORY;
+          break;
+        }
+        if(state->uploadfile) {
+          per->uploadfile = strdup(state->uploadfile);
+          if(!per->uploadfile) {
+            curl_easy_cleanup(curl);
+            result = CURLE_OUT_OF_MEMORY;
+            break;
+          }
+        }
+        *added = TRUE;
+        per->config = config;
+        per->curl = curl;
+        per->urlnum = urlnode->num;
+        per->etag_save = etag_first; /* copy the whole struct */
+
+        /* default headers output stream is stdout */
+        heads = &per->heads;
+        heads->stream = stdout;
+
+        /* Single header file for all URLs */
+        if(config->headerfile) {
+          /* open file for output: */
+          if(strcmp(config->headerfile, "-")) {
+            FILE *newfile;
+            newfile = fopen(config->headerfile, per->prev == NULL?"wb":"ab");
+            if(!newfile) {
+              warnf(global, "Failed to open %s\n", config->headerfile);
+              result = CURLE_WRITE_ERROR;
+              break;
+            }
+            else {
+              heads->filename = config->headerfile;
+              heads->s_isreg = TRUE;
+              heads->fopened = TRUE;
+              heads->stream = newfile;
+            }
+          }
+          else {
+            /* always use binary mode for protocol header output */
+            set_binmode(heads->stream);
+          }
+        }
+
+        hdrcbdata = &per->hdrcbdata;
+
+        outs = &per->outs;
+        input = &per->input;
+
+        per->outfile = NULL;
+        per->infdopen = FALSE;
+        per->infd = STDIN_FILENO;
+
+        /* default output stream is stdout */
+        outs->stream = stdout;
+
         if(state->urls) {
           result = glob_next_url(&per->this_url, state->urls);
           if(result)
@@ -2305,8 +2309,12 @@ static CURLcode serial_transfers(struct GlobalConfig *global,
   bool added = FALSE;
 
   result = create_transfer(global, share, &added);
-  if(result || !added)
+  if(result)
     return result;
+  if(!added) {
+    errorf(global, "no transfer performed\n");
+    return CURLE_READ_ERROR;
+  }
   for(per = transfers; per;) {
     bool retry;
     long delay;