From 3b00c6f79d1960e2867ea71e93fdfd28582774a4 Mon Sep 17 00:00:00 2001
From: Kefu Chai <tchaikov@gmail.com>
Date: Wed, 26 Nov 2014 23:09:51 +0800
Subject: [PATCH] safe_io: do not set ending \0 in safe_read_file()

Signed-off-by: Kefu Chai <tchaikov@gmail.com>
---
 src/common/safe_io.c            |  3 +--
 src/test/Makefile.am            |  5 +++++
 src/test/common/test_safe_io.cc | 37 +++++++++++++++++++++++++++++++++
 3 files changed, 43 insertions(+), 2 deletions(-)
 create mode 100644 src/test/common/test_safe_io.cc

diff --git a/src/common/safe_io.c b/src/common/safe_io.c
index 492234972812..76fd25aca122 100644
--- a/src/common/safe_io.c
+++ b/src/common/safe_io.c
@@ -216,7 +216,7 @@ int safe_read_file(const char *base, const char *file,
   if (fd < 0) {
     return -errno;
   }
-  len = safe_read(fd, val, vallen - 1);
+  len = safe_read(fd, val, vallen);
   if (len < 0) {
     VOID_TEMP_FAILURE_RETRY(close(fd));
     return len;
@@ -224,6 +224,5 @@ int safe_read_file(const char *base, const char *file,
   // close sometimes returns errors, but only after write()
   VOID_TEMP_FAILURE_RETRY(close(fd));
 
-  val[len] = 0;
   return len;
 }
diff --git a/src/test/Makefile.am b/src/test/Makefile.am
index c114a9c7b9e0..de1f5d608387 100644
--- a/src/test/Makefile.am
+++ b/src/test/Makefile.am
@@ -529,6 +529,11 @@ unittest_context_LDADD = $(UNITTEST_LDADD) $(CEPH_GLOBAL)
 unittest_context_CXXFLAGS = $(UNITTEST_CXXFLAGS)
 check_PROGRAMS += unittest_context
 
+unittest_safe_io_SOURCES = test/common/test_safe_io.cc
+unittest_safe_io_LDADD = $(UNITTEST_LDADD) $(CEPH_GLOBAL)
+unittest_safe_io_CXXFLAGS = $(UNITTEST_CXXFLAGS)
+check_PROGRAMS += unittest_safe_io
+
 unittest_heartbeatmap_SOURCES = test/heartbeat_map.cc
 unittest_heartbeatmap_LDADD = $(LIBCOMMON) $(UNITTEST_LDADD) $(CEPH_GLOBAL)
 unittest_heartbeatmap_CXXFLAGS = $(UNITTEST_CXXFLAGS)
diff --git a/src/test/common/test_safe_io.cc b/src/test/common/test_safe_io.cc
new file mode 100644
index 000000000000..b54437d6a8f4
--- /dev/null
+++ b/src/test/common/test_safe_io.cc
@@ -0,0 +1,37 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+
+#include <algorithm>
+#include <cstring>
+#include <fcntl.h>
+#include <unistd.h>
+
+#include "common/safe_io.h"
+
+#include "gtest/gtest.h"
+
+
+TEST(SafeIO, safe_read_file) {
+  const char *fname = "safe_read_testfile";
+  ::unlink(fname);
+  int fd = ::open(fname, O_RDWR|O_CREAT|O_TRUNC, 0600);
+  ASSERT_NE(fd, -1);
+  const char buf[] = "0123456789";
+  for (int i = 0; i < 8; i++) {
+    ASSERT_EQ(sizeof(buf), write(fd, buf, sizeof(buf)));
+  }
+  ::close(fd);
+  char rdata[80];
+  ASSERT_EQ(sizeof(rdata),
+	    safe_read_file(".", fname, rdata, sizeof(rdata)));
+  for (char *p = rdata, *end = rdata+sizeof(rdata); p < end; p+=sizeof(buf)) {
+    ASSERT_EQ(0, std::memcmp(p, buf, std::min(size_t(end-p), sizeof(buf))));
+  }
+  ::unlink(fname);
+}
+
+// Local Variables:
+// compile-command: "cd ../.. ;
+//   make unittest_safe_io &&
+//   ./unittest_safe_io"
+// End:
-- 
2.47.3