objcopy renaming section with explicit flags

This tidies SEC_RELOC handling in bfd, in the process fixing a bug
with objcopy when renaming sections.

bfd/
	* reloc.c (_bfd_generic_set_reloc): Set/clear SEC_RELOC depending
	on reloc count.
	* elf64-sparc.c (elf64_sparc_set_reloc): Likewise.
binutils/
	* objcopy.c (copy_relocations_in_section): Remove now unnecessary
	clearing of SEC_RELOC.
	* testsuite/binutils-all/rename-section-01.d: New test.
	* testsuite/binutils-all/objcopy.exp: Run it.
gas/
	* write.c (size_seg): Remove unneccesary twiddle of SEC_RELOC.
	(write_relocs): Likewise.  Always call bfd_set_reloc.
diff --git a/bfd/elf64-sparc.c b/bfd/elf64-sparc.c
index fb4483d..c6d0d3e 100644
--- a/bfd/elf64-sparc.c
+++ b/bfd/elf64-sparc.c
@@ -322,6 +322,10 @@
 {
   asect->orelocation = location;
   canon_reloc_count (asect) = count;
+  if (count != 0)
+    asect->flags |= SEC_RELOC;
+  else
+    asect->flags &= ~SEC_RELOC;
 }
 
 /* Write out the relocs.  */
diff --git a/bfd/reloc.c b/bfd/reloc.c
index 89b6f7f..6446acc 100644
--- a/bfd/reloc.c
+++ b/bfd/reloc.c
@@ -8706,6 +8706,10 @@
 {
   section->orelocation = relptr;
   section->reloc_count = count;
+  if (count != 0)
+    section->flags |= SEC_RELOC;
+  else
+    section->flags &= ~SEC_RELOC;
 }
 
 /*
diff --git a/binutils/objcopy.c b/binutils/objcopy.c
index d886e3a..3d88624 100644
--- a/binutils/objcopy.c
+++ b/binutils/objcopy.c
@@ -4331,10 +4331,7 @@
     }
 
   if (relsize == 0)
-    {
-      bfd_set_reloc (obfd, osection, NULL, 0);
-      osection->flags &= ~SEC_RELOC;
-    }
+    bfd_set_reloc (obfd, osection, NULL, 0);
   else
     {
       if (isection->orelocation != NULL)
@@ -4377,8 +4374,6 @@
 	}
 
       bfd_set_reloc (obfd, osection, relcount == 0 ? NULL : relpp, relcount);
-      if (relcount == 0)
-	osection->flags &= ~SEC_RELOC;
     }
 }
 
diff --git a/binutils/testsuite/binutils-all/objcopy.exp b/binutils/testsuite/binutils-all/objcopy.exp
index 5871d43..aebfdb2 100644
--- a/binutils/testsuite/binutils-all/objcopy.exp
+++ b/binutils/testsuite/binutils-all/objcopy.exp
@@ -1448,3 +1448,5 @@
 if { ![is_xcoff_format] } {
     objcopy_test "pr25662" $src executable "" $ldflags
 }
+
+run_dump_test "rename-section-01"
diff --git a/binutils/testsuite/binutils-all/rename-section-01.d b/binutils/testsuite/binutils-all/rename-section-01.d
new file mode 100644
index 0000000..21d9013
--- /dev/null
+++ b/binutils/testsuite/binutils-all/rename-section-01.d
@@ -0,0 +1,14 @@
+#PROG: objcopy
+#name: objcopy rename-section with flags - keep relocation
+#source: needed-by-reloc.s
+#objcopy: --rename-section .data=myrodata,contents,alloc,load,readonly
+#objdump: -r
+#notarget: alpha*-*-*vms* rx-*-elf [is_som_format] [is_aout_format]
+
+.*: +file format .*
+
+#...
+RELOCATION RECORDS FOR .*myrodata.*:
+OFFSET +TYPE +VALUE
+0+ .*
+#pass
diff --git a/gas/write.c b/gas/write.c
index 1c1b810..3014f68 100644
--- a/gas/write.c
+++ b/gas/write.c
@@ -579,7 +579,6 @@
   if (size > 0 && ! seginfo->bss)
     flags |= SEC_HAS_CONTENTS;
 
-  flags &= ~SEC_RELOC;
   x = bfd_set_section_flags (sec, flags);
   gas_assert (x);
 
@@ -1385,13 +1384,7 @@
   }
 #endif
 
-  if (n)
-    {
-      flagword flags = bfd_section_flags (sec);
-      flags |= SEC_RELOC;
-      bfd_set_section_flags (sec, flags);
-      bfd_set_reloc (stdoutput, sec, relocs, n);
-    }
+  bfd_set_reloc (stdoutput, sec, n ? relocs : NULL, n);
 
 #ifdef SET_SECTION_RELOCS
   SET_SECTION_RELOCS (sec, relocs, n);