More FTP client debug fixes

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@3662 42af7a65-404d-4744-a932-0658087f49c3

3 files changed, 29 insertions, 13 deletions

diff --git a/nuttx/lib/stdio/lib_asprintf.c b/nuttx/lib/stdio/lib_asprintf.c
index 42467e71d..343f6dd86 100644
--- a/nuttx/lib/stdio/lib_asprintf.c
+++ b/nuttx/lib/stdio/lib_asprintf.c
@@ -99,18 +99,22 @@ int asprintf (FAR char **ptr, const char *fmt, ...)
   struct lib_memoutstream_s memoutstream;
   FAR char *buf;
   va_list ap;
-  int     n;
+  int     nbytes;
 
   DEBUGASSERT(ptr && fmt);
 
-  /* First, use a nullstream to get the size of the buffer */
+  /* First, use a nullstream to get the size of the buffer.  The number
+   * of bytes returned may or may not include the null terminator.
+   */
   
   lib_nulloutstream(&nulloutstream);
   va_start(ap, fmt);
-  n = lib_vsprintf((FAR struct lib_outstream_s *)&nulloutstream, fmt, ap);
+  nbytes = lib_vsprintf((FAR struct lib_outstream_s *)&nulloutstream, fmt, ap);
   va_end(ap);
 
-  /* Then allocate a buffer to hold that number of characters */
+  /* Then allocate a buffer to hold that number of characters, adding one
+   * for the null terminator.
+   */
 
   buf = (FAR char *)malloc(nulloutstream.nput + 1);
   if (!buf)
@@ -118,24 +122,29 @@ int asprintf (FAR char **ptr, const char *fmt, ...)
       return ERROR;
     }
 
-  /* Initialize a memory stream to write into the allocated buffer */
+  /* Initialize a memory stream to write into the allocated buffer.  The
+   * memory stream will reserve one byte at the end of the buffer for the
+   * null terminator and will not report this in the number of output bytes.
+   */
 
   lib_memoutstream((FAR struct lib_memoutstream_s *)&memoutstream,
-                   buf, nulloutstream.nput);
+                   buf, nulloutstream.nput + 1);
 
   /* Then let lib_vsprintf do it's real thing */
 
   va_start(ap, fmt);
-  n = lib_vsprintf((FAR struct lib_outstream_s *)&memoutstream.public, fmt, ap);
+  nbytes = lib_vsprintf((FAR struct lib_outstream_s *)&memoutstream.public, fmt, ap);
   va_end(ap);
 
-  /* Terminate the string and return a pointer to the string to the caller.
+  /* Return a pointer to the string to the caller.  NOTE: the memstream put()
+   * method has already added the NUL terminator to the end of the string (not
+   * included in the nput count).
+   *
    * Hmmm.. looks like the memory would be stranded if lib_vsprintf() returned
    * an error.  Does that ever happen?
    */
 
-  DEBUGASSERT(n < 0 || n == nulloutstream.nput);
-  buf[nulloutstream.nput] = '\0';
+  DEBUGASSERT(nbytes < 0 || nbytes == nulloutstream.nput);
   *ptr = buf;
-  return n;
+  return nbytes;
 }
diff --git a/nuttx/lib/stdio/lib_meminstream.c b/nuttx/lib/stdio/lib_meminstream.c
index 6e1db7c2c..839e56219 100644
--- a/nuttx/lib/stdio/lib_meminstream.c
+++ b/nuttx/lib/stdio/lib_meminstream.c
@@ -52,7 +52,7 @@ static int meminstream_getc(FAR struct lib_instream_s *this)
   FAR struct lib_meminstream_s *mthis = (FAR struct lib_meminstream_s *)this;
   int ret;
 
-  if (this && this->nget < mthis->buflen - 1)
+  if (this && this->nget < mthis->buflen)
     {
       ret = mthis->buffer[this->nget];
       this->nget++;
diff --git a/nuttx/lib/stdio/lib_memoutstream.c b/nuttx/lib/stdio/lib_memoutstream.c
index d5a673b3a..dca8456e8 100644
--- a/nuttx/lib/stdio/lib_memoutstream.c
+++ b/nuttx/lib/stdio/lib_memoutstream.c
@@ -50,7 +50,13 @@
 static void memoutstream_putc(FAR struct lib_outstream_s *this, int ch)
 {
   FAR struct lib_memoutstream_s *mthis = (FAR struct lib_memoutstream_s *)this;
-  if (this && this->nput < mthis->buflen - 1)
+
+  /* If this will not overrun the buffer, then write the character to the
+   * buffer.  Not that buflen was pre-decremented when the stream was
+   * created so it is okay to write past the end of the buflen by one.
+   */
+
+  if (this && this->nput < mthis->buflen)
     {
       mthis->buffer[this->nput] = ch;
       this->nput++;
@@ -89,6 +95,7 @@ void lib_memoutstream(FAR struct lib_memoutstream_s *memoutstream,
   memoutstream->public.nput  = 0;          /* Will be buffer index */
   memoutstream->buffer       = bufstart;   /* Start of buffer */
   memoutstream->buflen       = buflen - 1; /* Save space for null terminator */
+  memoutstream->buffer[0]    = '\0';       /* Start with an empty string */
 }