t/test-lib: introduce ZERO_OID

diff --git a/t/t0028-working-tree-encoding.sh b/t/t0028-working-tree-encoding.sh
index a318d03232d2b6130b25ad5c7b9d163179d9a29c..12b8eb963a525e4083f96b7d9edc28858d90a1e7 100755 (executable)
--- a/t/t0028-working-tree-encoding.sh
+++ b/t/t0028-working-tree-encoding.sh
@@ -4,6 +4,8 @@ test_description='working-tree-encoding conversion via gitattributes'
 
 . ./test-lib.sh
 
+GIT_TRACE_WORKING_TREE_ENCODING=1 && export GIT_TRACE_WORKING_TREE_ENCODING
+
 test_expect_success 'setup test files' '
        git config core.eol lf &&
 
@@ -201,4 +203,43 @@ test_expect_success 'error if encoding garbage is already in Git' '
        test_i18ngrep "error: BOM is required" err.out
 '
 
+test_expect_success 'check roundtrip encoding' '
+       test_when_finished "rm -f roundtrip.shift roundtrip.utf16" &&
+       test_when_finished "git reset --hard HEAD" &&
+
+       text="hallo there!\nroundtrip test here!" &&
+       printf "$text" | iconv -f UTF-8 -t SHIFT-JIS >roundtrip.shift &&
+       printf "$text" | iconv -f UTF-8 -t UTF-16 >roundtrip.utf16 &&
+       echo "*.shift text working-tree-encoding=SHIFT-JIS" >>.gitattributes &&
+
+       # SHIFT-JIS encoded files are round-trip checked by default...
+       GIT_TRACE=1 git add .gitattributes roundtrip.shift 2>&1 |
+               grep "Checking roundtrip encoding for SHIFT-JIS" &&
+       git reset &&
+
+       # ... unless we overwrite the Git config!
+       ! GIT_TRACE=1 git -c core.checkRoundtripEncoding=garbage \
+               add .gitattributes roundtrip.shift 2>&1 |
+               grep "Checking roundtrip encoding for SHIFT-JIS" &&
+       git reset &&
+
+       # UTF-16 encoded files should not be round-trip checked by default...
+       ! GIT_TRACE=1 git add roundtrip.utf16 2>&1 |
+               grep "Checking roundtrip encoding for UTF-16" &&
+       git reset &&
+
+       # ... unless we tell Git to check it!
+       GIT_TRACE=1 git -c core.checkRoundtripEncoding="UTF-16, UTF-32" \
+               add roundtrip.utf16 2>&1 |
+               grep "Checking roundtrip encoding for utf-16" &&
+       git reset &&
+
+       # ... unless we tell Git to check it!
+       # (here we also check that the casing of the encoding is irrelevant)
+       GIT_TRACE=1 git -c core.checkRoundtripEncoding="UTF-32, utf-16" \
+               add roundtrip.utf16 2>&1 |
+               grep "Checking roundtrip encoding for utf-16" &&
+       git reset
+'
+
 test_done