bin/136383: [PATCH] usr.bin/jot fix usage of uninitialized values

[Ulrich Spoerlein]

>Number:         136383
>Category:       bin
>Synopsis:       [PATCH] usr.bin/jot fix usage of uninitialized values
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Mon Jul 06 16:20:01 UTC 2009
>Closed-Date:
>Last-Modified:
>Originator:     Ulrich Spörlein
>Release:        FreeBSD 7.2-STABLE i386
>Organization:
>Environment:
>Description:
A run of clang's static analyzer found that jot(1) has a bug regarding
the use of uninitialized variables.

https://www.spoerlein.net/scan-build/2009-07-04-1/report-BcTTXG.html#EndPath

The repetitions, start, end and step values are not preset. When defaults
are given, it will use "random" values for these.
>How-To-Repeat:
% jot -
0
0
% jot - -
0
0
0
% jot - - -
0
0
0
0
% jot - - - -
0
0
0
0
0

>Fix:

Simply pre-set all four variables to their defaults to match behaviour
claimed in manpage. Also add regression test for this case.

--- jot.diff begins here ---
Index: tools/regression/usr.bin/jot/regress.sh
===================================================================
--- tools/regression/usr.bin/jot/regress.sh	(revision 193930)
+++ tools/regression/usr.bin/jot/regress.sh	(working copy)
@@ -1,6 +1,6 @@
 # $FreeBSD$
 
-echo 1..56
+echo 1..57
 
 REGRESSION_START($1)
 
@@ -20,6 +20,7 @@
 REGRESSION_TEST(`ddhh', `jot - - 120 2')
 REGRESSION_TEST(`ddhd', `jot - - 120 -')
 REGRESSION_TEST(`dddh', `jot - - - 2')
+REGRESSION_TEST(`dddd', `jot - - - -')
 REGRESSION_TEST(`hhhh2', `jot 30 20 160 2')
 REGRESSION_TEST(`hhhd2', `jot 30 20 160 -')
 REGRESSION_TEST(`hhdh2', `jot 30 20 - 2')
Index: tools/regression/usr.bin/jot/regress.dddd.out
===================================================================
--- tools/regression/usr.bin/jot/regress.dddd.out	(revision 0)
+++ tools/regression/usr.bin/jot/regress.dddd.out	(revision 0)
@@ -0,0 +1,100 @@
+1
+2
+3
+4
+5
+6
+7
+8
+9
+10
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+12
+13
+14
+15
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+99
+100
Index: usr.bin/jot/jot.c
===================================================================
--- usr.bin/jot/jot.c	(revision 193930)
+++ usr.bin/jot/jot.c	(working copy)
@@ -101,13 +101,13 @@
 	int	ch;
 	int	mask = 0;
 	int	n = 0;
-	double	begin;
+	double	begin = BEGIN_DEF;
 	double	divisor;
-	double	ender;
-	double	s;
+	double	ender = ENDER_DEF;
+	double	s = STEP_DEF;
 	double	x, y;
 	long	i;
-	long	reps;
+	long	reps = REPS_DEF;
 
 	while ((ch = getopt(argc, argv, "b:cnp:rs:w:")) != -1)
 		switch (ch) {
--- jot.diff ends here ---


>Release-Note:
>Audit-Trail:
>Unformatted: