Testsuite fixes

* tests/sparse06.at: Skip the test if genfile is unable to create
sparse files.
* tests/sptrcreat.at: Likewise.
* tests/sptrdiff00.at: Likewise.
* tests/sptrdiff01.at: Likewise.

tests/sparse06.at

@@ -23,7 +23,7 @@ AT_KEYWORDS([sparse sparse06 chdir])
 
 m4_define([check_pattern],[
 rm -rf out archive.tar smallsparse && mkdir out
-genfile --sparse --quiet --file smallsparse $1
+genfile --sparse --quiet --file smallsparse $1 || AT_SKIP_TEST
 tar -cSf archive.tar smallsparse
 tar -xf archive.tar -C out
 cmp smallsparse out/smallsparse
@@ -33,7 +33,7 @@ AT_TAR_CHECK([
 AT_SEEKHOLE_PREREQ
 
 TAR_OPTIONS="$TAR_OPTIONS --hole-detection=seek"
-genfile --sparse --file bigsparse 0 ABC 8G DEF
+genfile --sparse --file bigsparse 0 ABC 8G DEF || AT_SKIP_TEST
 tar -cSf a bigsparse
 test $? -eq 0 || exit 1
 

tests/sptrcreat.at

@@ -35,7 +35,7 @@ AT_KEYWORDS([truncate filechange sparse sptr sptrcreat])
 
 AT_TAR_CHECK([
 genfile --sparse --block-size=1024 --file foo \
-  0 ABCDEFGHIJ 1M ABCDEFGHIJ 10M ABCDEFGHIJ 200M ABCDEFGHIJ
+  0 ABCDEFGHIJ 1M ABCDEFGHIJ 10M ABCDEFGHIJ 200M ABCDEFGHIJ || AT_SKIP_TEST
 genfile --file baz
 genfile --run --checkpoint 3 --length 200m --truncate foo -- \
  tar --sparse -vcf bar foo baz

tests/sptrdiff00.at

@@ -29,7 +29,7 @@ AT_KEYWORDS([truncate filechange sparse sptr sptrdiff diff])
 # This triggers short read in check_sparse_region.
 AT_TAR_CHECK([
 genfile --sparse --block-size=1024 --file foo \
-  0 ABCDEFGHIJ 1M ABCDEFGHIJ 10M ABCDEFGHIJ 200M ABCDEFGHIJ
+  0 ABCDEFGHIJ 1M ABCDEFGHIJ 10M ABCDEFGHIJ 200M ABCDEFGHIJ || AT_SKIP_TEST
 genfile --file baz
 echo creating
 tar --sparse -vcf bar foo baz

tests/sptrdiff01.at

@@ -29,7 +29,7 @@ AT_KEYWORDS([truncate filechange sparse sptr sptrdiff diff])
 # This triggers short read in check_data_region.
 AT_TAR_CHECK([
 genfile --sparse --block-size=1024 --file foo \
-  0 ABCDEFGHIJ 1M ABCDEFGHIJ 10M ABCDEFGHIJ 200M ABCDEFGHIJ
+  0 ABCDEFGHIJ 1M ABCDEFGHIJ 10M ABCDEFGHIJ 200M ABCDEFGHIJ || AT_SKIP_TEST
 genfile --file baz
 echo creating
 tar --sparse -vcf bar foo baz