libowfat/stralloc/stralloc_catm_internal.c

#include <stdarg.h>
#include <string.h>
#include "stralloc.h"

int stralloc_catm_internal(stralloc* sa, ...) {
  va_list a;
  const char* s;
  size_t n=0;
  va_start(a,sa);
  while ((s=va_arg(a,const char*))) {
    size_t tmp = strlen(s);
    if (n + tmp < n) return 0;	// integer overflow
    // integer overflow should not be possible, but someone could pass
    // the same string twice to provoke it. Better check than sorry.
    n += tmp;
  }
  va_end(a);
  stralloc_readyplus(sa,n);

  va_start(a,sa);
  while ((s=va_arg(a,const char*)))
    if (stralloc_cats(sa,s)==0) {
      va_end(a);
      return 0;
    }
  va_end(a);
  return 1;
}