list-objects.c: don't add an unparsed NULL as a pending tree

diff --git a/t/t4020-diff-external.sh b/t/t4020-diff-external.sh
index 637b4e19d52e81cf1472a4ed9dcfb0c9ff00da2b..22ef7d44b08ac7ec20e799a194e27205c794c290 100755 (executable)
--- a/t/t4020-diff-external.sh
+++ b/t/t4020-diff-external.sh
@@ -43,6 +43,13 @@ test_expect_success 'GIT_EXTERNAL_DIFF environment should apply only to diff' '
 
 '
 
+test_expect_success 'GIT_EXTERNAL_DIFF environment and --no-ext-diff' '
+
+       GIT_EXTERNAL_DIFF=echo git diff --no-ext-diff |
+       grep "^diff --git a/file b/file"
+
+'
+
 test_expect_success 'diff attribute' '
 
        git config diff.parrot.command echo &&
@@ -68,6 +75,13 @@ test_expect_success 'diff attribute should apply only to diff' '
 
 '
 
+test_expect_success 'diff attribute and --no-ext-diff' '
+
+       git diff --no-ext-diff |
+       grep "^diff --git a/file b/file"
+
+'
+
 test_expect_success 'diff attribute' '
 
        git config --unset diff.parrot.command &&
@@ -94,6 +108,13 @@ test_expect_success 'diff attribute should apply only to diff' '
 
 '
 
+test_expect_success 'diff attribute and --no-ext-diff' '
+
+       git diff --no-ext-diff |
+       grep "^diff --git a/file b/file"
+
+'
+
 test_expect_success 'no diff with -diff' '
        echo >.gitattributes "file -diff" &&
        git diff | grep Binary