[PATCH] Avoid warning when char is unsigned

[Mattias Engdegård]

This trivial non-essential patch avoids a warning when building with - 
Wall.

[[[
Avoid a "condition always true" warning on platforms where char
is unsigned by default, such as PowerPC and ARM.
* subversion/libsvn_subr/utf_validate.c
  (first_non_fsm_start_char, first_non_fsm_start_char_cstring):
   Add explicit cast to avoid warning when plain char is unsigned.
]]]
Index: utf_validate.c
===================================================================
--- utf_validate.c      (revision 1467576)
+++ utf_validate.c      (working copy)
@@ -271,7 +271,7 @@
       max_len -= len;
 
       for (; len > 0; ++data, --len)
-        if (*data < 0 || *data >= 0x80)
+        if ((unsigned char)*data >= 0x80)
           return data;
     }
 
@@ -285,7 +285,7 @@
 
   /* The remaining odd bytes will be examined the naive way: */
   for (; max_len > 0; ++data, --max_len)
-    if (*data < 0 || *data >= 0x80)
+    if ((unsigned char)*data >= 0x80)
       break;
 
   return data;
@@ -304,7 +304,7 @@
    * segfault.
    */
   for (; (apr_uintptr_t)data & (sizeof(apr_uintptr_t)-1); ++data)
-    if (*data <= 0 || *data >= 0x80)
+    if (*data == 0 || (unsigned char)*data >= 0x80)
       return data;
 
   /* Scan the input one machine word at a time. */
@@ -331,7 +331,7 @@
 
   /* The remaining odd bytes will be examined the naive way: */
   for (; ; ++data)
-    if (*data <= 0 || *data >= 0x80)
+    if (*data == 0 || (unsigned char)*data >= 0x80)
       break;
 
   return data;