1 files changed, 31 insertions, 32 deletions

diff --git a/docs/examples/smtp-authzid.c b/docs/examples/smtp-authzid.c
index decdb719d..b315b215c 100644
--- a/docs/examples/smtp-authzid.c
+++ b/docs/examples/smtp-authzid.c
@@ -5,11 +5,11 @@
  *                            | (__| |_| |  _ <| |___
  *                             \___|\___/|_| \_\_____|
  *
- * Copyright (C) 1998 - 2019, Daniel Stenberg, <daniel@haxx.se>, et al.
+ * Copyright (C) 1998 - 2021, 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 https://curl.haxx.se/docs/copyright.html.
+ * are also available at https://curl.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
@@ -47,41 +47,42 @@
 #define SENDER_MAIL  "Kurt " SENDER_ADDR
 #define TO_MAIL      "A Receiver " TO_ADDR
 
-static const char *payload_text[] = {
-  "Date: Mon, 29 Nov 2010 21:54:29 +1100\r\n",
-  "To: " TO_MAIL "\r\n",
-  "From: " FROM_MAIL "\r\n",
-  "Sender: " SENDER_MAIL "\r\n",
+static const char *payload_text =
+  "Date: Mon, 29 Nov 2010 21:54:29 +1100\r\n"
+  "To: " TO_MAIL "\r\n"
+  "From: " FROM_MAIL "\r\n"
+  "Sender: " SENDER_MAIL "\r\n"
   "Message-ID: <dcd7cb36-11db-487a-9f3a-e652a9458efd@"
-  "rfcpedant.example.org>\r\n",
-  "Subject: SMTP example message\r\n",
-  "\r\n", /* empty line to divide headers from body, see RFC5322 */
-  "The body of the message starts here.\r\n",
-  "\r\n",
-  "It could be a lot of lines, could be MIME encoded, whatever.\r\n",
-  "Check RFC5322.\r\n",
-  NULL
-};
+  "rfcpedant.example.org>\r\n"
+  "Subject: SMTP example message\r\n"
+  "\r\n" /* empty line to divide headers from body, see RFC5322 */
+  "The body of the message starts here.\r\n"
+  "\r\n"
+  "It could be a lot of lines, could be MIME encoded, whatever.\r\n"
+  "Check RFC5322.\r\n";
 
 struct upload_status {
-  int lines_read;
+  size_t bytes_read;
 };
 
-static size_t payload_source(void *ptr, size_t size, size_t nmemb, void *userp)
+static size_t payload_source(char *ptr, size_t size, size_t nmemb, void *userp)
 {
   struct upload_status *upload_ctx = (struct upload_status *)userp;
   const char *data;
+  size_t room = size * nmemb;
 
   if((size == 0) || (nmemb == 0) || ((size*nmemb) < 1)) {
     return 0;
   }
 
-  data = payload_text[upload_ctx->lines_read];
+  data = &payload_text[upload_ctx->bytes_read];
 
   if(data) {
     size_t len = strlen(data);
+    if(room < len)
+      len = room;
     memcpy(ptr, data, len);
-    upload_ctx->lines_read++;
+    upload_ctx->bytes_read += len;
 
     return len;
   }
@@ -94,9 +95,7 @@ int main(void)
   CURL *curl;
   CURLcode res = CURLE_OK;
   struct curl_slist *recipients = NULL;
-  struct upload_status upload_ctx;
-
-  upload_ctx.lines_read = 0;
+  struct upload_status upload_ctx = { 0 };
 
   curl = curl_easy_init();
   if(curl) {
@@ -114,7 +113,7 @@ int main(void)
     /* Force PLAIN authentication */
     curl_easy_setopt(curl, CURLOPT_LOGIN_OPTIONS, "AUTH=PLAIN");
 
-    /* Note that this option isn't strictly required, omitting it will result
+    /* Note that this option is not strictly required, omitting it will result
      * in libcurl sending the MAIL FROM command with empty sender data. All
      * autoresponses should have an empty reverse-path, and should be directed
      * to the address in the reverse-path which triggered them. Otherwise,
@@ -128,7 +127,7 @@ int main(void)
     recipients = curl_slist_append(recipients, TO_ADDR);
     curl_easy_setopt(curl, CURLOPT_MAIL_RCPT, recipients);
 
-    /* We're using a callback function to specify the payload (the headers and
+    /* We are using a callback function to specify the payload (the headers and
      * body of the message). You could just use the CURLOPT_READDATA option to
      * specify a FILE pointer to read from. */
     curl_easy_setopt(curl, CURLOPT_READFUNCTION, payload_source);
@@ -146,13 +145,13 @@ int main(void)
     /* Free the list of recipients */
     curl_slist_free_all(recipients);
 
-    /* curl won't send the QUIT command until you call cleanup, so you should
-     * be able to re-use this connection for additional messages (setting
-     * CURLOPT_MAIL_FROM and CURLOPT_MAIL_RCPT as required, and calling
-     * curl_easy_perform() again. It may not be a good idea to keep the
-     * connection open for a very long time though (more than a few minutes
-     * may result in the server timing out the connection), and you do want to
-     * clean up in the end.
+    /* curl will not send the QUIT command until you call cleanup, so you
+     * should be able to re-use this connection for additional messages
+     * (setting CURLOPT_MAIL_FROM and CURLOPT_MAIL_RCPT as required, and
+     * calling curl_easy_perform() again. It may not be a good idea to keep
+     * the connection open for a very long time though (more than a few
+     * minutes may result in the server timing out the connection), and you do
+     * want to clean up in the end.
      */
     curl_easy_cleanup(curl);
   }