[PATCH] tools/xl: Fix trim() following c/s e316316 "xl: Rewrite trim()"

[Andrew Cooper <andrew.cooper3@citrix.com>]

c/s e316316 "xl: Rewrite trim()" uses the wrong indirection of
'output', causing memory corruption for all callers.

Introduce a new local variable, making the code more obviously
correct.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
CC: Ian Campbell <Ian.Campbell@citrix.com>
CC: Ian Jackson <Ian.Jackson@eu.citrix.com>
CC: Wei Liu <wei.liu2@citrix.com>
---
 tools/libxl/xl_cmdimpl.c |    8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/tools/libxl/xl_cmdimpl.c b/tools/libxl/xl_cmdimpl.c
index 37d4af6..0cc9f8b 100644
--- a/tools/libxl/xl_cmdimpl.c
+++ b/tools/libxl/xl_cmdimpl.c
@@ -663,10 +663,12 @@ static void trim(char_predicate_t predicate, const char *input, char **output)
         ;
 
     size_t len_nonnull = after - first;
+    char *result = xmalloc(len_nonnull + 1);
 
-    *output = xmalloc(len_nonnull + 1);
-    memcpy(output, first, len_nonnull);
-    output[len_nonnull] = 0;
+    memcpy(result, first, len_nonnull);
+    result[len_nonnull] = 0;
+
+    *output = result;
 }
 
 static int split_string_into_pair(const char *str,
-- 
1.7.10.4