CURLOPT_OPENSOCKETFUNCTION: return error at once

When CURL_SOCKET_BAD is returned in the callback, it should be treated
as an error (CURLE_COULDNT_CONNECT) if no other socket is subsequently
created when trying to connect to a server.

Bug: http://curl.haxx.se/mail/lib-2015-06/0047.html

lib/connect.c

@@ -1166,8 +1166,11 @@ CURLcode Curl_connecthost(struct connectdata *conn,  /* context */
     conn->tempaddr[0] = conn->tempaddr[0]->ai_next;
   }
 
-  if(conn->tempsock[0] == CURL_SOCKET_BAD)
+  if(conn->tempsock[0] == CURL_SOCKET_BAD) {
+    if(!result)
+      result = CURLE_COULDNT_CONNECT;
     return result;
+  }
 
   data->info.numconnects++; /* to track the number of connections made */
 

tests/data/Makefile.inc

@@ -153,7 +153,7 @@ test1516 \
 \
 test1520 \
 \
-test1525 test1526 test1527 test1528 test1529 \
+test1525 test1526 test1527 test1528 test1529 test1530 \
 \
 test1600 test1601 test1602 \
 \

tests/data/test1530

@@ -0,0 +1,27 @@
+<testcase>
+<info>
+<keywords>
+CURLOPT_OPENSOCKETFUNCTION
+</keywords>
+</info>
+
+<client>
+<server>
+none
+</server>
+<tool>
+lib1530
+</tool>
+ <name>
+CURLOPT_OPENSOCKETFUNCTION returns bad socket
+ </name>
+</client>
+
+# it should be detected and an error should be reported
+<verify>
+# 7 == CURLE_COULDNT_CONNECT
+<errorcode>
+7
+</errorcode>
+</verify>
+</testcase>

tests/libtest/Makefile.inc

@@ -23,7 +23,7 @@ noinst_PROGRAMS = chkhostname libauthretry libntlmconnect                \
  lib1500 lib1501 lib1502 lib1503 lib1504 lib1505 lib1506 lib1507 lib1508 \
  lib1509 lib1510 lib1511 lib1512 lib1513 lib1514 lib1515 \
  lib1520 \
- lib1525 lib1526 lib1527 lib1528 lib1529 \
+ lib1525 lib1526 lib1527 lib1528 lib1529 lib1530 \
  lib1900 \
  lib2033
 
@@ -380,6 +380,10 @@ lib1529_SOURCES = lib1529.c $(SUPPORTFILES) $(TESTUTIL) $(WARNLESS)
 lib1529_LDADD = $(TESTUTIL_LIBS)
 lib1529_CPPFLAGS = $(AM_CPPFLAGS) -DLIB1529
 
+lib1530_SOURCES = lib1530.c $(SUPPORTFILES) $(TESTUTIL) $(WARNLESS)
+lib1530_LDADD = $(TESTUTIL_LIBS)
+lib1530_CPPFLAGS = $(AM_CPPFLAGS) -DLIB1530
+
 lib1900_SOURCES = lib1900.c $(SUPPORTFILES) $(TESTUTIL) $(WARNLESS)
 lib1900_LDADD = $(TESTUTIL_LIBS)
 lib1900_CPPFLAGS = $(AM_CPPFLAGS)

tests/libtest/lib1530.c

@@ -0,0 +1,67 @@
+/***************************************************************************
+ *                                  _   _ ____  _
+ *  Project                     ___| | | |  _ \| |
+ *                             / __| | | | |_) | |
+ *                            | (__| |_| |  _ <| |___
+ *                             \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 1998 - 2015, 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
+ * are also available at http://curl.haxx.se/docs/copyright.html.
+ *
+ * You may opt to use, copy, modify, merge, publish, distribute and/or sell
+ * copies of the Software, and permit persons to whom the Software is
+ * furnished to do so, under the terms of the COPYING file.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ***************************************************************************/
+
+#include "test.h"
+
+#include "memdebug.h"
+
+static curl_socket_t opensocket(void *clientp,
+                                curlsocktype purpose,
+                                struct curl_sockaddr *address)
+{
+  (void)purpose;
+  (void)address;
+  (void)clientp;
+  fprintf(stderr, "opensocket() returns CURL_SOCKET_BAD\n");
+  return CURL_SOCKET_BAD;
+}
+
+int test(char *URL)
+{
+  CURL *curl = NULL;
+  CURLcode res = CURLE_FAILED_INIT;
+  (void)URL;
+
+  if(curl_global_init(CURL_GLOBAL_ALL) != CURLE_OK) {
+    fprintf(stderr, "curl_global_init() failed\n");
+    return TEST_ERR_MAJOR_BAD;
+  }
+
+  if((curl = curl_easy_init()) == NULL) {
+    fprintf(stderr, "curl_easy_init() failed\n");
+    curl_global_cleanup();
+    return TEST_ERR_MAJOR_BAD;
+  }
+
+  test_setopt(curl, CURLOPT_URL, "http://99.99.99.99:9999");
+  test_setopt(curl, CURLOPT_VERBOSE, 1L);
+  test_setopt(curl, CURLOPT_OPENSOCKETFUNCTION, opensocket);
+
+  res = curl_easy_perform(curl);
+
+test_cleanup:
+
+  curl_easy_cleanup(curl);
+  curl_global_cleanup();
+
+  return (int)res;
+}