From 18193e8f005320db5ce47067f076680bef7d7532 Mon Sep 17 00:00:00 2001
From: Alexandre Oliva <oliva@adacore.com>
Date: Thu, 16 Jan 2020 03:58:50 -0300
Subject: [PATCH] [libiberty] output empty args as a pair of quotes

writeargv writes out empty arguments in a way that expandargv skips
them instead of preserving them.  Fixed by writing out a pair of
quotes for them.


for  libiberty/ChangeLog

	* argv.c (writeargv): Output empty args as "".
---
 libiberty/ChangeLog | 4 ++++
 libiberty/argv.c    | 8 ++++++++
 2 files changed, 12 insertions(+)

diff --git a/libiberty/ChangeLog b/libiberty/ChangeLog
index c2bab93a151..17903ea1be5 100644
--- a/libiberty/ChangeLog
+++ b/libiberty/ChangeLog
@@ -1,3 +1,7 @@
+2020-01-23  Alexandre Oliva <oliva@adacore.com>
+
+	* argv.c (writeargv): Output empty args as "".
+
 2020-01-01  Jakub Jelinek  <jakub@redhat.com>
 
 	Update copyright years.
diff --git a/libiberty/argv.c b/libiberty/argv.c
index 8c9794db6a2..6a72208d845 100644
--- a/libiberty/argv.c
+++ b/libiberty/argv.c
@@ -327,6 +327,14 @@ writeargv (char * const *argv, FILE *f)
           arg++;
         }
 
+      /* Write out a pair of quotes for an empty argument.  */
+      if (arg == *argv)
+	if (EOF == fputs ("\"\"", f))
+	  {
+	    status = 1;
+	    goto done;
+	  }
+
       if (EOF == fputc ('\n', f))
         {
           status = 1;