Add test to set interpreter of same name

tests/Makefile.am

@@ -52,7 +52,8 @@ src_TESTS = \
   overlapping-segments-after-rounding.sh \
   shared-rpath.sh \
   short-first-segment.sh \
-  empty-note.sh
+  empty-note.sh \
+  set-interpreter-same.sh
 
 build_TESTS = \
   $(no_rpath_arch_TESTS)

tests/set-interpreter-same.sh

@@ -0,0 +1,56 @@
+#! /bin/sh -e
+SCRATCH=scratch/$(basename "$0" .sh)
+
+./simple
+
+curInterpreter=$(../src/patchelf --print-interpreter ./simple)
+echo "current interpreter is $curInterpreter"
+
+rm -rf "${SCRATCH}"
+mkdir -p "${SCRATCH}"
+
+cp simple "${SCRATCH}"/
+
+echo "set the same interpreter as the current one"
+before_checksum=$(sha256sum ${SCRATCH}/simple)
+../src/patchelf --set-interpreter "${curInterpreter}" "${SCRATCH}/simple"
+after_checksum=$(sha256sum ${SCRATCH}/simple)
+
+if [ "$before_checksum" != "$after_checksum" ]; then
+    echo "--set-interpreter should be NOP, but the file has been changed."
+    exit 1
+fi
+
+${SCRATCH}/simple
+
+dummyInterpreter="aaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
+
+echo "set the dummy interpreter"
+before_checksum=$(sha256sum ${SCRATCH}/simple)
+../src/patchelf --set-interpreter "${dummyInterpreter}" "${SCRATCH}/simple"
+after_checksum=$(sha256sum ${SCRATCH}/simple)
+
+if [ "$before_checksum" = "$after_checksum" ]; then
+    echo "--set-interpreter should be run, but the file has not been changed."
+    exit 1
+fi
+
+if "${SCRATCH}/simple"; then
+    echo "simple works, but it shouldn't"
+    exit 1
+fi
+
+echo "set the same interpreter as the current one"
+before_checksum=$(sha256sum ${SCRATCH}/simple)
+../src/patchelf --set-interpreter "${dummyInterpreter}" "${SCRATCH}/simple"
+after_checksum=$(sha256sum ${SCRATCH}/simple)
+
+if [ "$before_checksum" != "$after_checksum" ]; then
+    echo "--set-interpreter should be NOP, but the file has been changed."
+    exit 1
+fi
+
+if "${SCRATCH}/simple"; then
+    echo "simple works, but it shouldn't"
+    exit 1
+fi