title: strcat + strlen has strange behavior
body: <p>guys i want to find the cause why this strcat (or strlen) has this issue:</p>
  
  <p>when i write:</p>
  
  <pre><code>int main(int argc, char* argv[])
  {
      if(argv[1] != '\0')
      {
          const char* navegador = "C:\\Program Files\\Mozilla Firefox\\firefox.exe ";
          const char* puerto  = "localhost:80/";
          char* archivo   = argv[1];
  
              char comando[2] = "\"";
              strcat(comando,navegador);
              int size = strlen(comando);         // ISSUE UNCOMMENTED!
  
          printf("command is: %s\n",comando);
      }
      else
      {
          printf("is null!\n");
      }
      return 0;
  }
  </code></pre>
  
  <p>its output is:</p>
  
  <pre><code>D:\camil\Documents\mis_documentos\configs\sublime_text&gt;program.exe someOption
  command is: "C:\.
  </code></pre>
  
  <p>and when i comment the issue statement, its output is:</p>
  
  <pre><code>D:\camil\Documents\mis_documentos\configs\sublime_text&gt;program.exe someOption
  command is: "C:\Program Files\Mozilla Firefox\firefox.exe"
  </code></pre>
  
  <p>Why strlen changes the output, it seems strlen affects strcat behavior.</p>