Store a PGresult in the Exception error

This makes the Diagnostics independent from further operations on the cursor
and allows using it with exceptions not generated by a cursor.

psycopg/cursor_type.c

@@ -118,7 +118,7 @@ _mogrify(PyObject *var, PyObject *fmt, cursorObject *curs, PyObject **new)
             if (kind == 2) {
                 Py_XDECREF(n);
                 psyco_set_error(ProgrammingError, curs,
-                   "argument formats can't be mixed", NULL, NULL);
+                   "argument formats can't be mixed");
                 return -1;
             }
             kind = 1;
@@ -190,7 +190,7 @@ _mogrify(PyObject *var, PyObject *fmt, cursorObject *curs, PyObject **new)
                 /* we found %( but not a ) */
                 Py_XDECREF(n);
                 psyco_set_error(ProgrammingError, curs,
-                   "incomplete placeholder: '%(' without ')'", NULL, NULL);
+                   "incomplete placeholder: '%(' without ')'");
                 return -1;
             }
             c = d + 1;  /* after the ) */
@@ -205,7 +205,7 @@ _mogrify(PyObject *var, PyObject *fmt, cursorObject *curs, PyObject **new)
             if (kind == 1) {
                 Py_XDECREF(n);
                 psyco_set_error(ProgrammingError, curs,
-                  "argument formats can't be mixed", NULL, NULL);
+                  "argument formats can't be mixed");
                 return -1;
             }
             kind = 2;
@@ -267,7 +267,7 @@ static PyObject *_psyco_curs_validate_sql_basic(
 
     if (!sql || !PyObject_IsTrue(sql)) {
         psyco_set_error(ProgrammingError, self,
-                         "can't execute an empty query", NULL, NULL);
+                         "can't execute an empty query");
         goto fail;
     }
 
@@ -338,8 +338,7 @@ _psyco_curs_merge_query_args(cursorObject *self,
                 if (!strcmp(s, "not enough arguments for format string")
                   || !strcmp(s, "not all arguments converted")) {
                     Dprintf("psyco_curs_execute:     -> got a match");
-                    psyco_set_error(ProgrammingError, self,
+                    psyco_set_error(ProgrammingError, self, s);
-                                     s, NULL, NULL);
                     pe = 1;
                 }
 
@@ -482,13 +481,12 @@ psyco_curs_execute(cursorObject *self, PyObject *args, PyObject *kwargs)
     if (self->name != NULL) {
         if (self->query != Py_None) {
             psyco_set_error(ProgrammingError, self,
-                "can't call .execute() on named cursors more than once",
+                "can't call .execute() on named cursors more than once");
-                NULL, NULL);
             return NULL;
         }
         if (self->conn->autocommit) {
             psyco_set_error(ProgrammingError, self,
-                "can't use a named cursor outside of transactions", NULL, NULL);
+                "can't use a named cursor outside of transactions");
             return NULL;
         }
         EXC_IF_NO_MARK(self);
@@ -533,7 +531,7 @@ psyco_curs_executemany(cursorObject *self, PyObject *args, PyObject *kwargs)
 
     if (self->name != NULL) {
         psyco_set_error(ProgrammingError, self,
-                "can't call .executemany() on named cursors", NULL, NULL);
+                "can't call .executemany() on named cursors");
         return NULL;
     }
 
@@ -1038,7 +1036,7 @@ psyco_curs_callproc(cursorObject *self, PyObject *args)
 
     if (self->name != NULL) {
         psyco_set_error(ProgrammingError, self,
-                         "can't call .callproc() on named cursors", NULL, NULL);
+                         "can't call .callproc() on named cursors");
         goto exit;
     }
 
@@ -1165,13 +1163,13 @@ psyco_curs_scroll(cursorObject *self, PyObject *args, PyObject *kwargs)
             newpos = value;
         } else {
             psyco_set_error(ProgrammingError, self,
-                "scroll mode must be 'relative' or 'absolute'", NULL, NULL);
+                "scroll mode must be 'relative' or 'absolute'");
             return NULL;
         }
 
         if (newpos < 0 || newpos >= self->rowcount ) {
             psyco_set_error(ProgrammingError, self,
-                             "scroll destination out of bounds", NULL, NULL);
+                             "scroll destination out of bounds");
             return NULL;
         }
 

psycopg/diagnostics.h

@@ -26,12 +26,14 @@
 #ifndef PSYCOPG_DIAGNOSTICS_H
 #define PSYCOPG_DIAGNOSTICS_H 1
 
+#include "psycopg/error.h"
+
 extern HIDDEN PyTypeObject diagnosticsType;
 
 typedef struct {
     PyObject_HEAD
 
-    PyObject *err;           /* exception to retrieve the diagnostics from */
+    PsycoErrorObject *err;  /* exception to retrieve the diagnostics from */
 
 } diagnosticsObject;
 

psycopg/diagnostics_type.c

@@ -27,7 +27,7 @@
 #include "psycopg/psycopg.h"
 
 #include "psycopg/diagnostics.h"
-#include "psycopg/cursor.h"
+#include "psycopg/error.h"
 
 /* These are new in PostgreSQL 9.3. Defining them here so that psycopg2 can
  * use them with a 9.3+ server even if compiled against pre-9.3 headers. */
@@ -55,27 +55,15 @@
 static PyObject *
 psyco_diagnostics_get_field(diagnosticsObject *self, void *closure)
 {
-    // closure contains the field code.
+    const char *errortext;
-    PyObject *rv = NULL;
+
-    PyObject *curs = NULL;
+    if (!self->err->pgres) {
-    const char* errortext;
+        Py_INCREF(Py_None);
-    if (!(curs = PyObject_GetAttrString(self->err, "cursor")) ||
+        return Py_None;
-        !PyObject_TypeCheck(curs, &cursorType) ||
-        ((cursorObject *)curs)->pgres == NULL) {
-        goto exit;
     }
-    errortext = PQresultErrorField(
+
-        ((cursorObject *)curs)->pgres, (Py_intptr_t) closure);
+    errortext = PQresultErrorField(self->err->pgres, (Py_intptr_t) closure);
-    if (errortext) {
+    return error_text_from_chars(self->err, errortext);
-        rv = conn_text_from_chars(((cursorObject *)curs)->conn, errortext);
-    }
-exit:
-    if (!rv) {
-        rv = Py_None;
-        Py_INCREF(rv);
-    }
-    Py_XDECREF(curs);
-    return rv;
 }
 
 
@@ -134,8 +122,14 @@ diagnostics_init(diagnosticsObject *self, PyObject *args, PyObject *kwds)
     if (!PyArg_ParseTuple(args, "O", &err))
         return -1;
 
+    if (!PyObject_TypeCheck(err, &ErrorType)) {
+        PyErr_SetString(PyExc_TypeError,
+            "The argument must be a psycopg2.Error");
+        return -1;
+    }
+
     Py_INCREF(err);
-    self->err = err;
+    self->err = (PsycoErrorObject *)err;
     return 0;
 }
 

psycopg/error.h

@@ -34,7 +34,10 @@ typedef struct {
     PyObject *pgerror;
     PyObject *pgcode;
     cursorObject *cursor;
-    PGresult *result;
+    char *codec;
+    PGresult *pgres;
 } PsycoErrorObject;
 
+HIDDEN PyObject *error_text_from_chars(PsycoErrorObject *self, const char *str);
+
 #endif /* PSYCOPG_ERROR_H */

psycopg/error_type.c

@@ -31,6 +31,23 @@
 #include "psycopg/pqpath.h"
 
 
+PyObject *
+error_text_from_chars(PsycoErrorObject *self, const char *str)
+{
+    if (str == NULL) {
+        Py_INCREF(Py_None);
+        return (Py_None);
+    }
+
+#if PY_MAJOR_VERSION < 3
+        return PyString_FromString(str);
+#else
+        return PyUnicode_Decode(str, strlen(str),
+            self->codec ? self->codec : "ascii", "replace");
+#endif
+}
+
+
 static const char pgerror_doc[] =
     "The error message returned by the backend, if available, else None";
 
@@ -40,6 +57,9 @@ static const char pgcode_doc[] =
 static const char cursor_doc[] =
     "The cursor that raised the exception, if available, else None";
 
+static const char diag_doc[] =
+    "A Diagnostics object to get further information about the error";
+
 static PyMemberDef error_members[] = {
     { "pgerror", T_OBJECT, offsetof(PsycoErrorObject, pgerror),
         READONLY, (char *)pgerror_doc },
@@ -64,18 +84,12 @@ error_init(PsycoErrorObject *self, PyObject *args, PyObject *kwargs)
             (PyObject *)self, args, kwargs) < 0) {
         return -1;
     }
-    Py_CLEAR(self->pgerror);
-    Py_CLEAR(self->pgcode);
-    Py_CLEAR(self->cursor);
-    IFCLEARPGRES(self->result);
     return 0;
 }
 
 static int
 error_traverse(PsycoErrorObject *self, visitproc visit, void *arg)
 {
-    Py_VISIT(self->pgerror);
-    Py_VISIT(self->pgcode);
     Py_VISIT(self->cursor);
     return ((PyTypeObject *)PyExc_StandardError)->tp_traverse(
         (PyObject *)self, visit, arg);
@@ -87,7 +101,8 @@ error_clear(PsycoErrorObject *self)
     Py_CLEAR(self->pgerror);
     Py_CLEAR(self->pgcode);
     Py_CLEAR(self->cursor);
-    IFCLEARPGRES(self->result);
+    PyMem_Free(self->codec);
+    IFCLEARPGRES(self->pgres);
     return ((PyTypeObject *)PyExc_StandardError)->tp_clear((PyObject *)self);
 }
 
@@ -107,9 +122,8 @@ error_get_diag(PsycoErrorObject *self, void *closure)
 }
 
 static struct PyGetSetDef error_getsets[] = {
-    { "diag", (getter)error_get_diag, NULL,
+    { "diag", (getter)error_get_diag, NULL, (char *)diag_doc },
-        "Database error diagnostics" },
+    { NULL }
-    {NULL}
 };
 
 

psycopg/lobject.h

@@ -78,13 +78,13 @@ RAISES_NEG HIDDEN int lobject_close(lobjectObject *self);
 #define EXC_IF_LOBJ_LEVEL0(self) \
 if (self->conn->autocommit) {                                       \
     psyco_set_error(ProgrammingError, NULL,                         \
-        "can't use a lobject outside of transactions", NULL, NULL); \
+        "can't use a lobject outside of transactions");             \
     return NULL;                                                    \
 }
 #define EXC_IF_LOBJ_UNMARKED(self) \
 if (self->conn->mark != self->mark) {                  \
     psyco_set_error(ProgrammingError, NULL,            \
-        "lobject isn't valid anymore", NULL, NULL);    \
+        "lobject isn't valid anymore");                \
     return NULL;                                       \
 }
 

psycopg/lobject_type.c

@@ -333,7 +333,7 @@ lobject_setup(lobjectObject *self, connectionObject *conn,
 
     if (conn->autocommit) {
         psyco_set_error(ProgrammingError, NULL,
-            "can't use a lobject outside of transactions", NULL, NULL);
+            "can't use a lobject outside of transactions");
         return -1;
     }
 

psycopg/microprotocols.c

@@ -203,7 +203,7 @@ microprotocols_adapt(PyObject *obj, PyObject *proto, PyObject *alt)
     /* else set the right exception and return NULL */
     PyOS_snprintf(buffer, 255, "can't adapt type '%s'",
         Py_TYPE(obj)->tp_name);
-    psyco_set_error(ProgrammingError, NULL, buffer, NULL, NULL);
+    psyco_set_error(ProgrammingError, NULL, buffer);
     return NULL;
 }
 

psycopg/pqpath.c

@@ -38,6 +38,7 @@
 #include "psycopg/green.h"
 #include "psycopg/typecast.h"
 #include "psycopg/pgtypes.h"
+#include "psycopg/error.h"
 
 #include <string.h>
 
@@ -149,15 +150,20 @@ exception_from_sqlstate(const char *sqlstate)
 
 /* pq_raise - raise a python exception of the right kind
 
-   This function should be called while holding the GIL. */
+   This function should be called while holding the GIL.
+
+   The function passes the ownership of the pgres to the returned exception,
+   wherer the pgres was the explicit argument or taken from the cursor.
+   So, after calling it curs->pgres will be set to null */
 
 RAISES static void
-pq_raise(connectionObject *conn, cursorObject *curs, PGresult *pgres)
+pq_raise(connectionObject *conn, cursorObject *curs, PGresult **pgres)
 {
     PyObject *exc = NULL;
     const char *err = NULL;
     const char *err2 = NULL;
     const char *code = NULL;
+    PyObject *pyerr = NULL;
 
     if (conn == NULL) {
         PyErr_SetString(DatabaseError,
@@ -171,13 +177,13 @@ pq_raise(connectionObject *conn, cursorObject *curs, PGresult *pgres)
         conn->closed = 2;
 
     if (pgres == NULL && curs != NULL)
-        pgres = curs->pgres;
+        pgres = &curs->pgres;
 
-    if (pgres) {
+    if (pgres && *pgres) {
-        err = PQresultErrorMessage(pgres);
+        err = PQresultErrorMessage(*pgres);
         if (err != NULL) {
             Dprintf("pq_raise: PQresultErrorMessage: err=%s", err);
-            code = PQresultErrorField(pgres, PG_DIAG_SQLSTATE);
+            code = PQresultErrorField(*pgres, PG_DIAG_SQLSTATE);
         }
     }
     if (err == NULL) {
@@ -210,7 +216,26 @@ pq_raise(connectionObject *conn, cursorObject *curs, PGresult *pgres)
     err2 = strip_severity(err);
     Dprintf("pq_raise: err2=%s", err2);
 
-    psyco_set_error(exc, curs, err2, err, code);
+    pyerr = psyco_set_error(exc, curs, err2);
+
+    if (pyerr && PyObject_TypeCheck(pyerr, &ErrorType)) {
+        PsycoErrorObject *perr = (PsycoErrorObject *)pyerr;
+
+        PyMem_Free(perr->codec);
+        psycopg_strdup(&perr->codec, conn->codec, 0);
+
+        Py_CLEAR(perr->pgerror);
+        perr->pgerror = error_text_from_chars(perr, err);
+
+        Py_CLEAR(perr->pgcode);
+        perr->pgcode = error_text_from_chars(perr, code);
+
+        IFCLEARPGRES(perr->pgres);
+        if (pgres && *pgres) {
+            perr->pgres = *pgres;
+            *pgres = NULL;
+        }
+    }
 }
 
 /* pq_set_critical, pq_resolve_critical - manage critical errors
@@ -388,14 +413,16 @@ pq_complete_error(connectionObject *conn, PGresult **pgres, char **error)
 {
     Dprintf("pq_complete_error: pgconn = %p, pgres = %p, error = %s",
             conn->pgconn, *pgres, *error ? *error : "(null)");
-    if (*pgres != NULL)
+    if (*pgres != NULL) {
-        pq_raise(conn, NULL, *pgres);
+        pq_raise(conn, NULL, pgres);
+        /* now *pgres is null */
+    }
     else if (*error != NULL) {
         PyErr_SetString(OperationalError, *error);
     } else {
         PyErr_SetString(OperationalError, "unknown error");
     }
-    IFCLEARPGRES(*pgres);
+
     if (*error) {
         free(*error);
         *error = NULL;
@@ -1509,8 +1536,6 @@ pq_fetch(cursorObject *curs, int no_result)
     default:
         Dprintf("pq_fetch: uh-oh, something FAILED: pgconn = %p", curs->conn);
         pq_raise(curs->conn, curs, NULL);
-        /* don't clear curs->pgres, because it contains detailed error
-           information */
         ex = -1;
         break;
     }

psycopg/psycopg.h

@@ -120,8 +120,7 @@ HIDDEN PyObject *psyco_GetDecimalType(void);
 typedef struct cursorObject cursorObject;
 
 /* some utility functions */
-RAISES HIDDEN void psyco_set_error(PyObject *exc, cursorObject *curs, const char *msg,
+RAISES HIDDEN PyObject *psyco_set_error(PyObject *exc, cursorObject *curs, const char *msg);
-                            const char *pgerror, const char *pgcode);
 
 HIDDEN char *psycopg_escape_string(PyObject *conn,
               const char *from, Py_ssize_t len, char *to, Py_ssize_t *tolen);

psycopg/psycopgmodule.c

@@ -512,11 +512,10 @@ psyco_errors_set(PyObject *type)
 
    Create a new error of the given type with extra attributes. */
 
-RAISES void
+/* TODO: may have been changed to BORROWED */
-psyco_set_error(PyObject *exc, cursorObject *curs, const char *msg,
+RAISES PyObject *
-                const char *pgerror, const char *pgcode)
+psyco_set_error(PyObject *exc, cursorObject *curs, const char *msg)
 {
-    PyObject *t;
     PyObject *pymsg;
     PyObject *err = NULL;
     connectionObject *conn = NULL;
@@ -532,31 +531,24 @@ psyco_set_error(PyObject *exc, cursorObject *curs, const char *msg,
     else {
         /* what's better than an error in an error handler in the morning?
          * Anyway, some error was set, refcount is ok... get outta here. */
-        return;
+        return NULL;
     }
 
     if (err && PyObject_TypeCheck(err, &ErrorType)) {
         PsycoErrorObject *perr = (PsycoErrorObject *)err;
         if (curs) {
+            Py_CLEAR(perr->cursor);
             Py_INCREF(curs);
             perr->cursor = curs;
         }
-
-        if (pgerror) {
-            if ((t = conn_text_from_chars(conn, pgerror))) {
-                perr->pgerror = t;
-            }
-        }
-
-        if (pgcode) {
-            if ((t = conn_text_from_chars(conn, pgcode))) {
-                perr->pgcode = t;
-            }
     }
 
+    if (err) {
         PyErr_SetObject(exc, err);
         Py_DECREF(err);
     }
+
+    return err;
 }
 
 

psycopg/utils.c

@@ -115,10 +115,16 @@ psycopg_escape_identifier_easy(const char *from, Py_ssize_t len)
  *
  * Store the return in 'to' and return 0 in case of success, else return -1
  * and raise an exception.
+ *
+ * If from is null, store null into to.
  */
 RAISES_NEG int
 psycopg_strdup(char **to, const char *from, Py_ssize_t len)
 {
+    if (!from) {
+        *to = NULL;
+        return 0;
+    }
     if (!len) { len = strlen(from); }
     if (!(*to = PyMem_Malloc(len + 1))) {
         PyErr_NoMemory();