TFTP: add option to suppress TFTP option requests (Part 2)

- Add tests.

- Add an example to CURLOPT_TFTP_NO_OPTIONS.3.

- Add --tftp-no-options to expose CURLOPT_TFTP_NO_OPTIONS.

Bug: https://github.com/curl/curl/issues/481

2 files changed, 46 insertions, 16 deletions

diff --git a/docs/libcurl/opts/CURLOPT_TFTP_NO_OPTIONS.3 b/docs/libcurl/opts/CURLOPT_TFTP_NO_OPTIONS.3
index 0e31a2937..53b1770be 100644
--- a/docs/libcurl/opts/CURLOPT_TFTP_NO_OPTIONS.3
+++ b/docs/libcurl/opts/CURLOPT_TFTP_NO_OPTIONS.3
@@ -20,24 +20,51 @@
 .\" *
 .\" **************************************************************************
 .\"
-.TH CURLOPT_TFTP_NO_OPTIONS 3 "19 Jun 2014" "libcurl 7.37.0" "curl_easy_setopt options"
+.TH CURLOPT_TFTP_NO_OPTIONS 3 "23 Feb 2016" "libcurl 7.48.0" "curl_easy_setopt options"
 .SH NAME
-CURLOPT_TFTP_NO_OPTIONS \- Prevents TFTP options to be send with RRQs/WRQs
+CURLOPT_TFTP_NO_OPTIONS \- Do not send TFTP options requests.
 .SH SYNOPSIS
 #include <curl/curl.h>
 
-CURLcode curl_easy_setopt(CURL *handle, CURLOPT_TFTP_NO_OPTIONS, long sendoptions);
+CURLcode curl_easy_setopt(CURL *handle, CURLOPT_TFTP_NO_OPTIONS, long onoff);
 .SH DESCRIPTION
-Set \fIsendoptions\fP to 1 to exclude all TFTP options defined in RFC2347,
-RFC2348, RFC2349 from read and write requests.
-libcurl will behave like a client implementing only RFC1350, ignoring any
-protocol extensions.
+Set \fIonoff\fP to 1L to exclude all TFTP options defined in RFC2347, RFC2348
+and RFC2349 from read and write requests (RRQs/WRQs).
+
+This option improves interop with some legacy servers that do not acknowledge
+or properly implement TFTP options. When this option is used
+\fICURLOPT_TFTP_BLKSIZE(3)\fP is ignored.
 .SH DEFAULT
 0
 .SH PROTOCOLS
 TFTP
 .SH EXAMPLE
-TODO
+.nf
+size_t write_callback(char *ptr, size_t size, size_t nmemb, void *fp)
+{
+  return fwrite(ptr, size, nmemb, (FILE *)fp);
+}
+
+CURL *curl = curl_easy_init();
+if(curl) {
+  FILE *fp = fopen("foo.bin", "wb");
+  if(fp) {
+    curl_easy_setopt(curl, CURLOPT_WRITEDATA, (void *)fp);
+    curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, write_callback);
+
+    curl_easy_setopt(curl, CURLOPT_URL, "tftp://example.com/foo.bin");
+
+    /* do not send TFTP options requests */
+    curl_easy_setopt(curl, CURLOPT_TFTP_NO_OPTIONS, 1L);
+
+    /* Perform the request */
+    curl_easy_perform(curl);
+
+    fclose(fp);
+  }
+  curl_easy_cleanup(curl);
+}
+.fi
 .SH AVAILABILITY
 Added in 7.48.0
 .SH RETURN VALUE
diff --git a/docs/libcurl/opts/Makefile.am b/docs/libcurl/opts/Makefile.am
index 5c35ef92a..04f8b4bbe 100644
--- a/docs/libcurl/opts/Makefile.am
+++ b/docs/libcurl/opts/Makefile.am
@@ -97,11 +97,12 @@ man_MANS = CURLOPT_ACCEPT_ENCODING.3 CURLOPT_ACCEPTTIMEOUT_MS.3		\
  CURLOPT_SSL_VERIFYPEER.3 CURLOPT_SSL_VERIFYSTATUS.3			\
  CURLOPT_SSLVERSION.3 CURLOPT_STDERR.3 CURLOPT_TCP_KEEPALIVE.3		\
  CURLOPT_TCP_KEEPIDLE.3 CURLOPT_TCP_KEEPINTVL.3 CURLOPT_TCP_NODELAY.3	\
- CURLOPT_TELNETOPTIONS.3 CURLOPT_TFTP_BLKSIZE.3 CURLOPT_TIMECONDITION.3	\
- CURLOPT_TIMEOUT.3 CURLOPT_TIMEOUT_MS.3 CURLOPT_TIMEVALUE.3		\
- CURLOPT_TLSAUTH_PASSWORD.3 CURLOPT_TLSAUTH_TYPE.3			\
- CURLOPT_TLSAUTH_USERNAME.3 CURLOPT_TRANSFER_ENCODING.3			\
- CURLOPT_TRANSFERTEXT.3 CURLOPT_UNRESTRICTED_AUTH.3 CURLOPT_UPLOAD.3	\
+ CURLOPT_TELNETOPTIONS.3 CURLOPT_TFTP_BLKSIZE.3				\
+ CURLOPT_TFTP_NO_OPTIONS.3 CURLOPT_TIMECONDITION.3 CURLOPT_TIMEOUT.3	\
+ CURLOPT_TIMEOUT_MS.3 CURLOPT_TIMEVALUE.3 CURLOPT_TLSAUTH_PASSWORD.3	\
+ CURLOPT_TLSAUTH_TYPE.3 CURLOPT_TLSAUTH_USERNAME.3			\
+ CURLOPT_TRANSFER_ENCODING.3 CURLOPT_TRANSFERTEXT.3			\
+ CURLOPT_UNRESTRICTED_AUTH.3 CURLOPT_UPLOAD.3				\
  CURLOPT_URL.3 CURLOPT_USERAGENT.3 CURLOPT_USERNAME.3 CURLOPT_USERPWD.3	\
  CURLOPT_USE_SSL.3 CURLOPT_VERBOSE.3 CURLOPT_WILDCARDMATCH.3		\
  CURLOPT_WRITEDATA.3 CURLOPT_WRITEFUNCTION.3 CURLOPT_XFERINFODATA.3	\
@@ -224,8 +225,9 @@ HTMLPAGES = CURLOPT_ACCEPT_ENCODING.html CURLOPT_ACCEPTTIMEOUT_MS.html	\
  CURLOPT_SSLVERSION.html CURLOPT_STDERR.html CURLOPT_TCP_KEEPALIVE.html	\
  CURLOPT_TCP_KEEPIDLE.html CURLOPT_TCP_KEEPINTVL.html			\
  CURLOPT_TCP_NODELAY.html CURLOPT_TELNETOPTIONS.html			\
- CURLOPT_TFTP_BLKSIZE.html CURLOPT_TIMECONDITION.html			\
- CURLOPT_TIMEOUT.html CURLOPT_TIMEOUT_MS.html CURLOPT_TIMEVALUE.html	\
+ CURLOPT_TFTP_BLKSIZE.html CURLOPT_TFTP_NO_OPTIONS.html			\
+ CURLOPT_TIMECONDITION.html CURLOPT_TIMEOUT.html			\
+ CURLOPT_TIMEOUT_MS.html CURLOPT_TIMEVALUE.html				\
  CURLOPT_TLSAUTH_PASSWORD.html CURLOPT_TLSAUTH_TYPE.html		\
  CURLOPT_TLSAUTH_USERNAME.html CURLOPT_TRANSFER_ENCODING.html		\
  CURLOPT_TRANSFERTEXT.html CURLOPT_UNRESTRICTED_AUTH.html		\
@@ -354,7 +356,8 @@ PDFPAGES = CURLOPT_ACCEPT_ENCODING.pdf CURLOPT_ACCEPTTIMEOUT_MS.pdf	\
  CURLOPT_SSLVERSION.pdf CURLOPT_STDERR.pdf CURLOPT_TCP_KEEPALIVE.pdf	\
  CURLOPT_TCP_KEEPIDLE.pdf CURLOPT_TCP_KEEPINTVL.pdf			\
  CURLOPT_TCP_NODELAY.pdf CURLOPT_TELNETOPTIONS.pdf			\
- CURLOPT_TFTP_BLKSIZE.pdf CURLOPT_TIMECONDITION.pdf CURLOPT_TIMEOUT.pdf	\
+ CURLOPT_TFTP_BLKSIZE.pdf CURLOPT_TFTP_NO_OPTIONS.pdf			\
+ CURLOPT_TIMECONDITION.pdf CURLOPT_TIMEOUT.pdf				\
  CURLOPT_TIMEOUT_MS.pdf CURLOPT_TIMEVALUE.pdf				\
  CURLOPT_TLSAUTH_PASSWORD.pdf CURLOPT_TLSAUTH_TYPE.pdf			\
  CURLOPT_TLSAUTH_USERNAME.pdf CURLOPT_TRANSFER_ENCODING.pdf		\