fix setting empty rpath

Author: Mic92

src/patchelf.cc

@@ -1479,7 +1479,7 @@ void ElfFile<ElfFileParamNames>::modifyRPath(RPathOp op,
     debug("new rpath is '%s'\n", newRPath.c_str());
 
 
-    if (newRPath.size() <= rpathSize) {
+    if (rpath && newRPath.size() <= rpathSize) {
         memcpy(rpath, newRPath.c_str(), newRPath.size() + 1);
         return;
     }

tests/Makefile.am

@@ -31,7 +31,8 @@ src_TESTS = \
   invalid-elf.sh \
   endianness.sh \
   contiguous_note_sections.sh \
-  no-gnu-hash.sh
+  no-gnu-hash.sh \
+  set-empty-rpath.sh
 
 build_TESTS = \
   $(no_rpath_arch_TESTS)

tests/set-empty-rpath.sh

@@ -0,0 +1,11 @@
+#! /bin/sh -e
+SCRATCH=scratch/$(basename $0 .sh)
+
+rm -rf ${SCRATCH}
+mkdir -p ${SCRATCH}
+
+cp simple ${SCRATCH}/simple
+
+../src/patchelf --force-rpath --set-rpath "" ${SCRATCH}/simple
+
+${SCRATCH}/simple