Fix buggy usage of vsnprintf in PL/Python by removing it altogether, instead

relying on stringinfo.c.  This fixes a problem reported by Marko Kreen, but I
didn't use his patch, per subsequent discussion.

diff --git a/src/pl/plpython/plpython.c b/src/pl/plpython/plpython.c
index e811776599e806ff942d9596ff25d1a13dce6ce1..f765a685caee8f6328edd4b2ca8a870211abfcac 100644 (file)
--- a/src/pl/plpython/plpython.c
+++ b/src/pl/plpython/plpython.c
@@ -29,7 +29,7 @@
  * MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
  *
  * IDENTIFICATION
- *     $Header: /cvsroot/pgsql/src/pl/plpython/plpython.c,v 1.41.2.3 2006/02/20 20:10:45 neilc Exp $
+ *     $Header: /cvsroot/pgsql/src/pl/plpython/plpython.c,v 1.41.2.4 2007/11/23 01:48:08 alvherre Exp $
  *
  *********************************************************************
  */
@@ -55,6 +55,7 @@
 #include "commands/trigger.h"
 #include "executor/spi.h"
 #include "fmgr.h"
+#include "lib/stringinfo.h"
 #include "nodes/makefuncs.h"
 #include "parser/parse_type.h"
 #include "tcop/tcopprot.h"
@@ -208,7 +209,6 @@ static char *PLy_procedure_name(PLyProcedure *);
 /* some utility functions
  */
 static void *PLy_malloc(size_t);
-static void *PLy_realloc(void *, size_t);
 static void PLy_free(void *);
 
 /* sub handlers for functions and triggers
@@ -2604,8 +2604,6 @@ PLy_procedure_name(PLyProcedure * proc)
  */
 
 static char *PLy_traceback(int *);
-static char *PLy_vprintf(const char *fmt, va_list ap);
-static char *PLy_printf(const char *fmt,...);
 
 void
 PLy_exception_set(PyObject * exc, const char *fmt,...)
@@ -2624,18 +2622,27 @@ void
 PLy_elog(int elevel, const char *fmt,...)
 {
        DECLARE_EXC();
-       va_list         ap;
-       char       *xmsg,
-                          *emsg;
+       char       *xmsg;
+       StringInfoData emsg;
        int                     xlevel;
 
        enter();
 
        xmsg = PLy_traceback(&xlevel);
 
-       va_start(ap, fmt);
-       emsg = PLy_vprintf(fmt, ap);
-       va_end(ap);
+       initStringInfo(&emsg);
+       for (;;)
+       {
+               va_list         ap;
+               bool            success;
+
+               va_start(ap, fmt);
+               success = appendStringInfoVA(&emsg, fmt, ap);
+               va_end(ap);
+               if (success)
+                       break;
+               enlargeStringInfo(&emsg, emsg.maxlen);
+       }
 
        SAVE_EXC();
        if (TRAP_EXC())
@@ -2647,19 +2654,19 @@ PLy_elog(int elevel, const char *fmt,...)
                 * elog called siglongjmp. cleanup, restore and reraise
                 */
                PLy_restart_in_progress += 1;
-               PLy_free(emsg);
+               pfree(emsg.data);
                if (xmsg)
-                       PLy_free(xmsg);
+                       pfree(xmsg);
                RERAISE_EXC();
        }
 
        ereport(elevel,
-                       (errmsg("plpython: %s", emsg),
+                       (errmsg("plpython: %s", emsg.data),
                         (xmsg) ? errdetail("%s", xmsg) : 0));
 
-       PLy_free(emsg);
+       pfree(emsg.data);
        if (xmsg)
-               PLy_free(xmsg);
+               pfree(xmsg);
 
        leave();
 
@@ -2675,8 +2682,8 @@ PLy_traceback(int *xlevel)
        PyObject   *eob,
                           *vob = NULL;
        char       *vstr,
-                          *estr,
-                          *xstr = NULL;
+                          *estr;
+       StringInfoData xstr;
 
        enter();
 
@@ -2710,7 +2717,8 @@ PLy_traceback(int *xlevel)
         * NULL here -- would an Assert() be more appropriate?
         */
        estr = eob ? PyString_AsString(eob) : "Unknown Exception";
-       xstr = PLy_printf("%s: %s", estr, vstr);
+       initStringInfo(&xstr);
+       appendStringInfo(&xstr, "%s: %s", estr, vstr);
 
        Py_DECREF(eob);
        Py_XDECREF(vob);
@@ -2729,49 +2737,7 @@ PLy_traceback(int *xlevel)
        Py_DECREF(e);
        leave();
 
-       return xstr;
-}
-
-char *
-PLy_printf(const char *fmt,...)
-{
-       va_list         ap;
-       char       *emsg;
-
-       va_start(ap, fmt);
-       emsg = PLy_vprintf(fmt, ap);
-       va_end(ap);
-       return emsg;
-}
-
-char *
-PLy_vprintf(const char *fmt, va_list ap)
-{
-       size_t          blen;
-       int                     bchar,
-                               tries = 2;
-       char       *buf;
-
-       blen = strlen(fmt) * 2;
-       if (blen < 256)
-               blen = 256;
-       buf = PLy_malloc(blen * sizeof(char));
-
-       while (1)
-       {
-               bchar = vsnprintf(buf, blen, fmt, ap);
-               if ((bchar > 0) && (bchar < blen))
-                       return buf;
-               if (tries-- <= 0)
-                       break;
-               if (blen > 0)
-                       blen = bchar + 1;
-               else
-                       blen *= 2;
-               buf = PLy_realloc(buf, blen);
-       }
-       PLy_free(buf);
-       return NULL;
+       return xstr.data;
 }
 
 /* python module code
@@ -2793,18 +2759,6 @@ PLy_malloc(size_t bytes)
        return ptr;
 }
 
-void *
-PLy_realloc(void *optr, size_t bytes)
-{
-       void       *nptr = realloc(optr, bytes);
-
-       if (nptr == NULL)
-               ereport(FATAL,
-                               (errcode(ERRCODE_OUT_OF_MEMORY),
-                                errmsg("out of memory")));
-       return nptr;
-}
-
 /* define this away
  */
 void