nanogui: Thread: textfield_settext free bug !

Hi all,

I noticed this in `ntextfield.c'. Is this a bug ?

static void textfield_settext (NTEXTFIELD * this, const char * text)
{   
   int maxsize;

   if (text && strlen(text) > 256) maxsize = strlen(text) + 1;
   else maxsize = 256;

   if (this->maxsize < maxsize) {
      if (this->textbuf) free(this->textbuf);
      if (this->textbuf = malloc(maxsize)) {
	 this->textbuf[0] = '\0';
	 this->maxsize = maxsize;
      } else this->maxsize = 0;
   }
   
   if (!this->textbuf) free(this->textbuf); <<<< !!!!
   if (text) this->textbuf = strdup(text);
   else this->textbuf = 0;

   if (text && this->textbuf) strcpy(this->textbuf,text);
   this->curpos = 0;
   this->firstpos = 0;
   
   n_widget_repaint(this);

}

I fail to follow what this section of code does :

   if (!this->textbuf) free(this->textbuf);
   if (text) this->textbuf = strdup(text);
   else this->textbuf = 0;


-- 
 Chris Johns, ####@####.####

: I noticed this in `ntextfield.c'. Is this a bug ?

Yep 

: 
: static void textfield_settext (NTEXTFIELD * this, const char * text)
: {   
:    int maxsize;
: 
:    if (text && strlen(text) > 256) maxsize = strlen(text) + 1;
:    else maxsize = 256;
: 
:    if (this->maxsize < maxsize) {
:       if (this->textbuf) free(this->textbuf);
:       if (this->textbuf = malloc(maxsize)) {
: this->textbuf[0] = '\0';
: this->maxsize = maxsize;
:       } else this->maxsize = 0;
:    }
:    
:    if (!this->textbuf) free(this->textbuf); <<<< !!!!
:    if (text) this->textbuf = strdup(text);
:    else this->textbuf = 0;
: 
:    if (text && this->textbuf) strcpy(this->textbuf,text);
:    this->curpos = 0;
:    this->firstpos = 0;
:    
:    n_widget_repaint(this);
: 
: }
: 
: I fail to follow what this section of code does :
: 
:    if (!this->textbuf) free(this->textbuf);
:    if (text) this->textbuf = strdup(text);
:    else this->textbuf = 0;

Well, the first if statement is wrong.  the second just sets
this->textbuf to NULL or strdup(text).  The first if
stmt is meant to free this->textbuf before overwriting it.

Vidar wrote the code some time ago, you might ask him about it.

Greg