Don't rely on realloc() to follow POSIX in handling a NULL pointer

diff --git a/ChangeLog b/ChangeLog
index 8da51112f312ad74ef636fd4aec3d0a2e9d92ef5..a3eff81d5e3efeeb1d709e06e104470b9449b4b0 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,8 @@
 2008-05-21  Peter Maydell  <pmaydell@chiark.greenend.org.uk>
 
+       * sbr/utils.c (mh_xrealloc): don't assume realloc() can
+       handle NULL pointers; some non-POSIX realloc()s can't.
+
        * sbr/dtimep.lex: add some table size declarations for the
        benefit of elderly lexes with small defaults.
 

diff --git a/sbr/utils.c b/sbr/utils.c
index d822995ba251ed46c8d8a14ffa332f23840d4970..7c4ddcf26e46fe4256c0d39e1835958b4ffa27d9 100644 (file)
--- a/sbr/utils.c
+++ b/sbr/utils.c
@@ -47,6 +47,10 @@ mh_xrealloc(void *ptr, size_t size)
 {
     void *memory;
 
+    /* Some non-POSIX realloc()s don't cope with realloc(NULL,sz) */
+    if (!ptr)
+        return mh_xmalloc(size);
+
     if (size == 0)
         adios(NULL, "Tried to realloc 0bytes");