read-cache.c: fix writing "link" index ext with null base oid

diff --git a/t/t9011-svn-da.sh b/t/t9011-svn-da.sh
index b38d16f9dbd6e6f575e12f81e7d6546f07e53f1f..ab1ef28fd991f4325ad3821ae0f7607d4f500810 100755 (executable)
--- a/t/t9011-svn-da.sh
+++ b/t/t9011-svn-da.sh
@@ -18,7 +18,7 @@ test_expect_success 'reject empty delta' '
 test_expect_success 'delta can empty file' '
        printf "SVNQ" | q_to_nul >clear.delta &&
        test-svn-fe -d preimage clear.delta 4 >actual &&
-       test_cmp empty actual
+       test_must_be_empty actual
 '
 
 test_expect_success 'reject svndiff2' '
@@ -29,7 +29,7 @@ test_expect_success 'reject svndiff2' '
 test_expect_success 'one-window empty delta' '
        printf "SVNQ%s" "QQQQQ" | q_to_nul >clear.onewindow &&
        test-svn-fe -d preimage clear.onewindow 9 >actual &&
-       test_cmp empty actual
+       test_must_be_empty actual
 '
 
 test_expect_success 'reject incomplete window header' '
@@ -50,7 +50,7 @@ test_expect_success 'two-window empty delta' '
        printf "SVNQ%s%s" "QQQQQ" "QQQQQ" | q_to_nul >clear.twowindow &&
        test-svn-fe -d preimage clear.twowindow 14 >actual &&
        test_must_fail test-svn-fe -d preimage clear.twowindow 13 &&
-       test_cmp empty actual
+       test_must_be_empty actual
 '
 
 test_expect_success 'noisy zeroes' '
@@ -60,7 +60,7 @@ test_expect_success 'noisy zeroes' '
                q_to_nul >clear.noisy &&
        len=$(wc -c <clear.noisy) &&
        test-svn-fe -d preimage clear.noisy $len &&
-       test_cmp empty actual
+       test_must_be_empty actual
 '
 
 test_expect_success 'reject variable-length int in magic' '
@@ -83,7 +83,7 @@ test_expect_success 'reject truncated integer' '
 test_expect_success 'nonempty (but unused) preimage view' '
        printf "SVNQ%b" "Q\003QQQ" | q_to_nul >clear.readpreimage &&
        test-svn-fe -d preimage clear.readpreimage 9 >actual &&
-       test_cmp empty actual
+       test_must_be_empty actual
 '
 
 test_expect_success 'preimage view: right endpoint cannot backtrack' '
@@ -99,7 +99,7 @@ test_expect_success 'preimage view: left endpoint can advance' '
                q_to_nul >clear.shrinkbacktrack &&
        test-svn-fe -d preimage clear.preshrink 14 >actual &&
        test_must_fail test-svn-fe -d preimage clear.shrinkbacktrack 14 &&
-       test_cmp empty actual
+       test_must_be_empty actual
 '
 
 test_expect_success 'preimage view: offsets compared by value' '
@@ -109,7 +109,7 @@ test_expect_success 'preimage view: offsets compared by value' '
                q_to_nul >clear.noisyadvance &&
        test_must_fail test-svn-fe -d preimage clear.noisybacktrack 15 &&
        test-svn-fe -d preimage clear.noisyadvance 15 &&
-       test_cmp empty actual
+       test_must_be_empty actual
 '
 
 test_expect_success 'preimage view: reject truncated preimage' '