diff: fix flag -B, cleanups and a couple more tests V2

function                                             old     new   delta
diffreg                                             1157    1268    +111
uni_range                                             51       -     -51

Signed-off-by: Matheus Izvekov <mizvekov@gmail.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 31 insertions, 0 deletions

diff --git a/testsuite/diff.tests b/testsuite/diff.tests
index f7bde2f5b..72ebb6c4c 100755
--- a/testsuite/diff.tests
+++ b/testsuite/diff.tests
@@ -44,6 +44,17 @@ testing "diff of stdin, twice" \
         "" \
         "stdin"
 
+testing "diff of empty file against nonempty one" \
+        "diff -u - input | $TRIM_TAB" \
+"\
+--- -
++++ input
+@@ -0,0 +1 @@
++a
+" \
+        "a\n" \
+        ""
+
 testing "diff -b treats EOF as whitespace" \
         'diff -ub - input; echo $?' \
         "0\n" \
@@ -56,6 +67,26 @@ testing "diff -b treats all spaces as equal" \
         "a \t c\n" \
         "a\t \tc\n"
 
+testing "diff -B ignores changes whose lines are all blank" \
+        'diff -uB - input; echo $?' \
+        "0\n" \
+        "a\n" \
+        "\na\n\n"
+
+testing "diff -B does not ignore changes whose lines are not all blank" \
+        "diff -uB - input | $TRIM_TAB" \
+"\
+--- -
++++ input
+@@ -1,3 +1 @@
+-
+-b
+-
++a
+" \
+        "a\n" \
+        "\nb\n\n"
+
 testing "diff always takes context from old file" \
         "diff -ub - input | $TRIM_TAB" \
 "\