Fix printf() field width parsing regression issue [#2309].

diff --git a/mingwrt/ChangeLog b/mingwrt/ChangeLog
index 033c55d..7347834 100644 (file)
--- a/mingwrt/ChangeLog
+++ b/mingwrt/ChangeLog
@@ -1,3 +1,12 @@
+2016-07-22  Keith Marshall  <keithmarshall@users.sourceforge.net>
+
+       Fix printf() field width parsing regression issue [#2309].
+
+       * mingwex/stdio/pformat.c (__imul10plus): Coerce any accumulated
+       negative total to zero; the only negative value to be handled is...
+       (PFORMAT_IGNORE): ...this; it ceases to be applicable, on first call
+       to __imul10plus(), to accumulate field width or precision.
+
 2016-07-17  Keith Marshall  <keithmarshall@users.sourceforge.net>
 
        Correct source package omission of msvcrt-xref subdirectory.

diff --git a/mingwrt/mingwex/stdio/pformat.c b/mingwrt/mingwex/stdio/pformat.c
index 9354e30..a40ef02 100644 (file)
--- a/mingwrt/mingwex/stdio/pformat.c
+++ b/mingwrt/mingwex/stdio/pformat.c
@@ -1752,10 +1752,13 @@ void __pformat_xldouble( long double x, __pformat_t *stream )
 static __pformat_inline__
 /* Inline helper to accumulate a running total of successive
  * decimal digits, optimized to use bitwise shifts to multiply
- * the total of more significant digits by ten.
+ * the total of more significant digits by ten; (note that we
+ * coerce negative totals to zero, since this implementation
+ * never needs to accumulate negative values, but it must be
+ * able to override an initial PFORMAT_IGNORE (-1) setting).
  */
 int __pformat_imul10plus( int total, int units )
-{ return units + ((total == 0) ? 0 : ((total + (total << 2)) << 1)); }
+{ return units + ((total >= 0) ? ((total + (total << 2)) << 1) : 0); }
 
 static
 int __pformat_read_arg_index( const char **fmt )
@@ -3110,21 +3113,18 @@ int __pformat( int flags, void *dest, int max, const char *fmt, va_list args )
            if( (state < PFORMAT_END) && isdigit( c ) )
            {
              if( state == PFORMAT_INIT )
-               /*
-                * Initial digits explicitly relate to field width...
+               /* Initial digits explicitly relate to field width...
                 */
                state = PFORMAT_SET_WIDTH;
 
              else if( state == PFORMAT_GET_PRECISION )
-               /*
-                * while those following a precision indicator
+               /* while those following a precision indicator
                 * explicitly relate to precision.
                 */
                state = PFORMAT_SET_PRECISION;
 
              if( width_spec )
-             {
-               /* We are accepting a width or precision specification;
+             { /* We are accepting a width or precision specification;
                 * add the units value represented by the current digit,
                 * to ten times the value accumulated so far.
                 */
@@ -3149,7 +3149,6 @@ int __pformat( int flags, void *dest, int max, const char *fmt, va_list args )
        */
       __pformat_putc( c, &stream );
   }
-
   /* Clean up the resource pool, which was allocated for local processing of
    * the passed-in argument vector in either sequential or random order.
    */