Rewrite code that broke under Mac OS (isxdigit with ++ in its argument).

git-svn-id: svn://vcs.exim.org/pcre/code/trunk@735 2f5784b3-3f2a-0410-8824-cb99058d5e15

2 files changed, 14 insertions, 1 deletions

diff --git a/ChangeLog b/ChangeLog
index 7495a54..4a5ee38 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -107,6 +107,13 @@ Version 8.20 10-Oct-2011
 20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
     fail to work when decoding hex characters in data strings in EBCDIC 
     environments. 
+    
+21. It appears that in at least one Mac OS environment, the isxdigit() function 
+    is implemented as a macro that evaluates to its argument more than once,
+    contravening the C 90 Standard (I haven't checked a later standard). There
+    was an instance in pcretest which caused it to go wrong when processing
+    \x{...} escapes in subject strings. The has been rewritten to avoid using 
+    things like p++ in the argument of isxdigit().
 
 
 Version 8.13 16-Aug-2011
diff --git a/pcretest.c b/pcretest.c
index 6aac2c2..8ac3a36 100644
--- a/pcretest.c
+++ b/pcretest.c
@@ -2346,7 +2346,13 @@ while (!done)
           {
           unsigned char *pt = p;
           c = 0;
-          while (isxdigit(*(++pt)))
+          
+          /* We used to have "while (isxdigit(*(++pt)))" here, but it fails
+          when isxdigit() is a macro that refers to its argument more than
+          once. This is banned by the C Standard, but apparently happens in at
+          least one MacOS environment. */
+          
+          for (pt++; isxdigit(*pt); pt++)
             c = c * 16 + tolower(*pt) - ((isdigit(*pt))? '0' : 'a' - 10);
           if (*pt == '}')
             {