Add another binbuf_write() bugfix from vanilla Pd.

This was committed on Christmas Eve, so it must be important. :)

"fixed error message handling in binbuf_write() which accessed stale
memory" by msp (Dec 24, 2019)

See pure-data/pure-data@99fb497c

pd/src/g_readwrite.c

@@ -16,6 +16,7 @@ file format as in the dialog window for data.
 #include "m_pd.h"
 #include "g_canvas.h"
 #include <string.h>
+#include <errno.h>
 
 /* object to assist in saving state by abstractions */
 static t_class *savestate_class;
@@ -968,7 +969,10 @@ static void canvas_savetofile(t_canvas *x, t_symbol *filename, t_symbol *dir,
     t_binbuf *b = binbuf_new();
     canvas_savetemplatesto(x, b, 1);
     canvas_saveto(x, b);
-    if (binbuf_write(b, filename->s_name, dir->s_name, 0)) sys_ouch();
+    errno = 0;
+    if (binbuf_write(b, filename->s_name, dir->s_name, 0))
+        post("%s/%s: %s", dir->s_name, filename->s_name,
+            (errno ? strerror(errno) : "write failed"));
     else
     {
             /* if not an abstraction, reset title bar and directory */ 

pd/src/m_binbuf.c

@@ -1063,11 +1063,7 @@ int binbuf_write(t_binbuf *x, char *filename, char *dir, int crflag)
     }
 
     if (!(f = sys_fopen(fbuf, "w")))
-    {
-        //fprintf(stderr, "open: ");
-        sys_unixerror(fbuf);
         goto fail;
-    }
     for (ap = x->b_vec, indx = x->b_n; indx--; ap++)
     {
         int length;
@@ -1079,10 +1075,7 @@ int binbuf_write(t_binbuf *x, char *filename, char *dir, int crflag)
         if (ep - bp < length)
         {
             if (fwrite(sbuf, bp-sbuf, 1, f) < 1)
-            {
-                sys_unixerror(fbuf);
                 goto fail;
-            }
             bp = sbuf;
         }
         if ((ap->a_type == A_SEMI || ap->a_type == A_COMMA) &&
@@ -1106,17 +1099,11 @@ int binbuf_write(t_binbuf *x, char *filename, char *dir, int crflag)
         }
     }
     if (fwrite(sbuf, bp-sbuf, 1, f) < 1)
-    {
-        sys_unixerror(fbuf);
         goto fail;
-    }
 
 
     if (fflush(f) != 0) 
-    {
-        sys_unixerror(fbuf);
         goto fail;
-    }
 
     if (deleteit)
         binbuf_free(x);

pd/src/m_pd.h

@@ -591,10 +591,6 @@ EXTERN void bug(const char *fmt, ...) __attribute__ ((format (printf, 1, 2)));
 EXTERN void pd_error(void *object, const char *fmt, ...) __attribute__ ((format (printf, 2, 3)));
 EXTERN void logpost(const void *object, const int level, const char *fmt, ...)
     ATTRIBUTE_FORMAT_PRINTF(3, 4);
-EXTERN void sys_logerror(const char *object, const char *s);
-EXTERN void sys_unixerror(const char *object);
-EXTERN void sys_ouch(void);
-
 
 /* ------------  system interface routines ------------------- */
 EXTERN int sys_isreadablefile(const char *name);

pd/src/s_print.c

@@ -312,24 +312,8 @@ void bug(const char *fmt, ...)
     dopost(buf);
 }
 
-    /* this isn't worked out yet. */
-static const char *errobject;
-static const char *errstring;
-
-void sys_logerror(const char *object, const char *s)
-{
-    errobject = object;
-    errstring = s;
-}
-
-void sys_unixerror(const char *object)
-{
-    errobject = object;
-    errstring = strerror(errno);
-}
-
-void sys_ouch(void)
-{
-    if (*errobject) error("%s: %s", errobject, errstring);
-    else error("%s", errstring);
-}
+    /* don't use these.  They're included for binary compatibility with
+    old externs but never worked and now do nothing. */
+void sys_logerror(const char *object, const char *s) {}
+void sys_unixerror(const char *object) {}
+void sys_ouch(void) {}