[patch, committed, libgfortran] PR85906 - Conditional jump depends on uninitialized value in write_integer

[Jerry DeLisle]

I biffed the ChangeLog on this with a flip of two digits on the PR 
number (fixed).

Anyway, the following was committed as obvious to trunk.  The 
BUF_STACK_SZ I bumped up because I noticed on PR85840 test case that 
even small kind floats were asking for a buffer size of 323. This avoids 
a few allocs for every write operation.

2018-05-26  Jerry DeLisle  <jvdeli...@gcc.gnu.org>

        PR libgfortran/85906
        * io/write.c (write_integer): Initialise the fnode format to
        FMT_NONE, used for list directed write.
        (BUF_STACK_SZ): Bump default buffer size up to avoid allocs on
        small stuff.


--- trunk/libgfortran/io/write.c        2018/05/26 17:30:52     260793
+++ trunk/libgfortran/io/write.c        2018/05/26 18:22:18     260795
@@ -1348,6 +1348,7 @@
     }
   f.u.integer.w = width;
   f.u.integer.m = -1;
+  f.format = FMT_NONE;
   write_decimal (dtp, &f, source, kind, (void *) gfc_itoa);
 }

@@ -1465,7 +1466,7 @@

 /* Floating point helper functions.  */

-#define BUF_STACK_SZ 256
+#define BUF_STACK_SZ 384

 static int
 get_precision (st_parameter_dt *dtp, const fnode *f, const char 
*source, int kind)