tool_operate: warn if too many output arguments were found

More output instructions than URLs is likely a user error.

Add test case 371 to verify

Closes #8210

tests/data/Makefile.inc

@@ -5,7 +5,7 @@
 #                            | (__| |_| |  _ <| |___
 #                             \___|\___/|_| \_\_____|
 #
-# Copyright (C) 1998 - 2021, Daniel Stenberg, <daniel@haxx.se>, et al.
+# Copyright (C) 1998 - 2022, Daniel Stenberg, <daniel@haxx.se>, et al.
 #
 # This software is licensed as described in the file COPYING, which
 # you should have received as part of this distribution. The terms
@@ -61,7 +61,7 @@ test334 test335 test336 test337 test338 test339 test340 test341 test342 \
 test343 test344 test345 test346 test347 test348 test349 test350 test351 \
 test352 test353 test354 test355 test356 test357 test358 test359 test360 \
 test361 test362 test363 test364 test365 test366 test367 test368 test369 \
-test370 \
+test370 test371 \
 \
 test392 test393 test394 test395 test396 test397 \
 \

tests/data/test371

@@ -0,0 +1,56 @@
+<testcase>
+<info>
+<keywords>
+HTTP
+HTTP GET
+</keywords>
+</info>
+
+#
+# Server-side
+<reply>
+<data nocheck="yes">
+HTTP/1.1 200 OK
+Date: Tue, 09 Nov 2010 14:49:00 GMT
+Server: test-server/fake
+Last-Modified: Tue, 13 Jun 2000 12:10:00 GMT
+ETag: "21025-dc7-39462498"
+Accept-Ranges: bytes
+Content-Length: 6
+Connection: close
+Content-Type: text/html
+Funny-head: yesyes
+
+-foo-
+</data>
+</reply>
+
+#
+# Client-side
+<client>
+<server>
+http
+</server>
+ <name>
+using more -o than URLs in the command line
+ </name>
+ <command>
+http://%HOSTIP:%HTTPPORT/%TESTNUMBER -o log/dump -o log/dump2 --no-progress-meter
+</command>
+</client>
+
+#
+# Verify data after the test has been "shot"
+<verify>
+<protocol>
+GET /%TESTNUMBER HTTP/1.1
+Host: %HOSTIP:%HTTPPORT
+User-Agent: curl/%VERSION
+Accept: */*
+
+</protocol>
+<stderr mode="text">
+Warning: Got more output options than URLs
+</stderr>
+</verify>
+</testcase>