Segmentation fault when command-line args are incorrectly specified.

[Explorer]

Tested in Systester 1.5.1 running on Ubuntu 13.04 (64-bit).
32-bit may be affected as well.

Steps to produce:
1. Build the CLI version of systester (or try an official binary like this: https://sourceforge.net/projects/systester/files/systester/1.5.0/systester-1.5.1-linux-amd64.tar.gz/download)
2. Run this: "./systester-cli -qcborwein"
3. Run this: "./systester-cli -gausslg"
4. Run this: "./systester-cli -threads"
5. Run this: "./systester-cli -turns"
6. Run this: "./systester-cli -qcborwein -test"

Actual result:
Step 2-5 shows "Segmentation fault (core dumped)", while Step 6 displays the help text.

Expected result:
All steps from 2 to 6 should display the help text.

Note:
I have a patch for this. It checks the argc before accessing the next element in argv array in order to prevent out-of-bound access,
https://dl.dropboxusercontent.com/u/70170658/misc/systester-cli-args-bounds.patch

[Explorer]

Repost a valid link for the patch because the link on first post no longer works (due to Dropbox system change)
https://www.dropbox.com/s/0x83b08tngi8ppf/systester-cli-args-bounds.patch?dl=0

diff -r -u a/cli/systester-cli.c b/cli/systester-cli.c
--- a/cli/systester-cli.c   2012-07-09 04:41:47.000000000 +0800
+++ b/cli/systester-cli.c   2013-07-20 10:12:01.368310441 +0800
@@ -206,7 +206,11 @@
        {
          algo = 0;
          arg++;
-         loops = determine_loops (argv[arg], algo);
+         if (arg < argc)
+       loops = determine_loops (argv[arg], algo);
+         else
+       loops = -1;
+
          if (loops == -1)
        {
          help ();
@@ -217,7 +221,11 @@
        {
          algo = 1;
          arg++;
-         loops = determine_loops (argv[arg], algo);
+         if (arg < argc)
+       loops = determine_loops (argv[arg], algo);
+         else
+       loops = -1;
+
          if (loops == -1)
        {
          help ();
@@ -227,7 +235,10 @@
      else if (strcmp (argv[arg], "-threads") == 0)
        {
          arg++;
-         threads = atoi (argv[arg]);
+         if (arg < argc)
+       threads = atoi (argv[arg]);
+         else
+       threads = 0;

          if (threads < 1)
        {
@@ -242,7 +253,11 @@
      else if (strcmp (argv[arg], "-turns") == 0)
        {
          arg++;
-         executions = atoi (argv[arg]);
+         if (arg < argc)
+       executions = atoi (argv[arg]);
+         else
+       executions = 1;
+
          if (executions < 1)
        executions = 1;
        }