add SKIP_KNOWN_BUGS and SKIP_INTERNET_TESTS to testsuite

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/testsuite/README b/testsuite/README
index b4719e6..3c52254 100644
--- a/testsuite/README
+++ b/testsuite/README
@@ -10,10 +10,24 @@
 should be a shell fragment that returns successfully if the test case passes,
 and unsuccessfully otherwise.
 
+Set SKIP_KNOWN_BUGS environment variable to any non-empty value
+to exclude tests which are known to fail.
+
+Set SKIP_INTERNET_TESTS to exclude tests which require working
+internet connection.
+
 If the test case relies on a certain feature, it should include the string
 "FEATURE: " followed by the name of the feature in a comment.  If it is always
 expected to fail, it should include the string "XFAIL" in a comment.
 
+
+Common causes of false positives:
+
+For busybox built against uclibc, /etc/TZ does not exist or does not match
+host system timezone setting. For glibc based host systems, timezona settings
+are in /etc/localtime.
+
+
 For the entire testsuite, the copyright is as follows:
 
 Copyright (C) 2001, 2002  Matt Kraai
diff --git a/testsuite/hostname/hostname-i-works b/testsuite/hostname/hostname-i-works
index 68a3e67..7299bff 100644
--- a/testsuite/hostname/hostname-i-works
+++ b/testsuite/hostname/hostname-i-works
@@ -1,2 +1,9 @@
-test x$(hostname -i) = x$(busybox hostname -i)
+test x"$SKIP_KNOWN_BUGS" != x"" && exit
 
+# Observed bug:
+# # ./busybox hostname -i
+# 127.0.0.1
+# # hostname -i
+# 127.0.0.1 10.0.0.2 10.32.10.45
+
+test x$(hostname -i) = x$(busybox hostname -i)
diff --git a/testsuite/ls/ls-l-works b/testsuite/ls/ls-l-works
index 1bad34b..ce08810 100644
--- a/testsuite/ls/ls-l-works
+++ b/testsuite/ls/ls-l-works
@@ -1,3 +1,7 @@
+test x"$SKIP_KNOWN_BUGS" != x"" && exit
+
+# busybox does not emit "total NNN" line
+
 [ -n "$d" ] || d=..
 LC_ALL=C ls -l "$d" > logfile.gnu
 LC_ALL=C busybox ls -l "$d" > logfile.bb
diff --git a/testsuite/ls/ls-s-works b/testsuite/ls/ls-s-works
index 0a9d752..8bf5c64 100644
--- a/testsuite/ls/ls-s-works
+++ b/testsuite/ls/ls-s-works
@@ -1,3 +1,7 @@
+test x"$SKIP_KNOWN_BUGS" != x"" && exit
+
+# busybox does not emit "total NNN" line
+
 [ -n "$d" ] || d=..
 LC_ALL=C ls -1s "$d" > logfile.gnu
 LC_ALL=C busybox ls -1s "$d" > logfile.bb
diff --git a/testsuite/taskset.tests b/testsuite/taskset.tests
index 2d3ebd7..53d7f10 100755
--- a/testsuite/taskset.tests
+++ b/testsuite/taskset.tests
@@ -1,5 +1,4 @@
 #!/bin/sh
-
 # Copyright 2006 Bernhard Reutner-Fischer
 # Licensed under GPL v2 or later, see file LICENSE for details.
 
diff --git a/testsuite/wget/wget--O-overrides--P b/testsuite/wget/wget--O-overrides--P
index fdb5d47..40a3a96 100644
--- a/testsuite/wget/wget--O-overrides--P
+++ b/testsuite/wget/wget--O-overrides--P
@@ -1,3 +1,5 @@
+test x"$SKIP_INTERNET_TESTS" != x"" && exit
+
 mkdir foo
 busybox wget -q -O index.html -P foo http://www.google.com/
 test -s index.html
diff --git a/testsuite/wget/wget-handles-empty-path b/testsuite/wget/wget-handles-empty-path
index 5b59183..01d60bd 100644
--- a/testsuite/wget/wget-handles-empty-path
+++ b/testsuite/wget/wget-handles-empty-path
@@ -1 +1,3 @@
+test x"$SKIP_INTERNET_TESTS" != x"" && exit
+
 busybox wget http://www.google.com
diff --git a/testsuite/wget/wget-retrieves-google-index b/testsuite/wget/wget-retrieves-google-index
index 7be9a80..f9dbb8b 100644
--- a/testsuite/wget/wget-retrieves-google-index
+++ b/testsuite/wget/wget-retrieves-google-index
@@ -1,2 +1,4 @@
+test x"$SKIP_INTERNET_TESTS" != x"" && exit
+
 busybox wget -q -O foo http://www.google.com/
 test -s foo
diff --git a/testsuite/wget/wget-supports--P b/testsuite/wget/wget-supports--P
index 9b4d095..bfe4ac4 100644
--- a/testsuite/wget/wget-supports--P
+++ b/testsuite/wget/wget-supports--P
@@ -1,3 +1,5 @@
+test x"$SKIP_INTERNET_TESTS" != x"" && exit
+
 mkdir foo
 busybox wget -q -P foo http://www.google.com/
 test -s foo/index.html