🌐 AI搜索 & 代理 主页
Skip to content

Commit bc43331

Browse files
tglsfdctglsfdc
committed
Fix lo_import and lo_export to return useful error messages more often.
I found that these functions tend to return -1 while leaving an empty error message string in the PGconn, if they suffer some kind of I/O error on the file. The reason is that lo_close, which thinks it's executed a perfectly fine SQL command, clears the errorMessage. The minimum-change workaround is to reorder operations here so that we don't fill the errorMessage until after lo_close.
1 parent f52c516 commit bc43331

File tree

1 file changed

+30
-15
lines changed

1 file changed

+30
-15
lines changed

‎src/interfaces/libpq/fe-lobj.c‎

Lines changed: 30 additions & 15 deletions
Original file line numberDiff line numberDiff line change
@@ -168,7 +168,7 @@ lo_truncate(PGconn *conn, int fd, size_t len)
168168
if (len > (size_t) INT_MAX)
169169
{
170170
printfPQExpBuffer(&conn->errorMessage,
171-
libpq_gettext("argument of lo_truncate exceeds integer range\n"));
171+
libpq_gettext("argument of lo_truncate exceeds integer range\n"));
172172
return -1;
173173
}
174174

@@ -219,7 +219,7 @@ lo_truncate64(PGconn *conn, int fd, pg_int64 len)
219219
if (conn->lobjfuncs->fn_lo_truncate64 == 0)
220220
{
221221
printfPQExpBuffer(&conn->errorMessage,
222-
libpq_gettext("cannot determine OID of function lo_truncate64\n"));
222+
libpq_gettext("cannot determine OID of function lo_truncate64\n"));
223223
return -1;
224224
}
225225

@@ -277,7 +277,7 @@ lo_read(PGconn *conn, int fd, char *buf, size_t len)
277277
if (len > (size_t) INT_MAX)
278278
{
279279
printfPQExpBuffer(&conn->errorMessage,
280-
libpq_gettext("argument of lo_read exceeds integer range\n"));
280+
libpq_gettext("argument of lo_read exceeds integer range\n"));
281281
return -1;
282282
}
283283

@@ -332,7 +332,7 @@ lo_write(PGconn *conn, int fd, const char *buf, size_t len)
332332
if (len > (size_t) INT_MAX)
333333
{
334334
printfPQExpBuffer(&conn->errorMessage,
335-
libpq_gettext("argument of lo_write exceeds integer range\n"));
335+
libpq_gettext("argument of lo_write exceeds integer range\n"));
336336
return -1;
337337
}
338338

@@ -423,7 +423,7 @@ lo_lseek64(PGconn *conn, int fd, pg_int64 offset, int whence)
423423
if (conn->lobjfuncs->fn_lo_lseek64 == 0)
424424
{
425425
printfPQExpBuffer(&conn->errorMessage,
426-
libpq_gettext("cannot determine OID of function lo_lseek64\n"));
426+
libpq_gettext("cannot determine OID of function lo_lseek64\n"));
427427
return -1;
428428
}
429429

@@ -598,7 +598,7 @@ lo_tell64(PGconn *conn, int fd)
598598
if (conn->lobjfuncs->fn_lo_tell64 == 0)
599599
{
600600
printfPQExpBuffer(&conn->errorMessage,
601-
libpq_gettext("cannot determine OID of function lo_tell64\n"));
601+
libpq_gettext("cannot determine OID of function lo_tell64\n"));
602602
return -1;
603603
}
604604

@@ -753,10 +753,16 @@ lo_import_internal(PGconn *conn, const char *filename, Oid oid)
753753

754754
if (nbytes < 0)
755755
{
756+
/* We must do lo_close before setting the errorMessage */
757+
int save_errno = errno;
758+
759+
(void) lo_close(conn, lobj);
760+
(void) close(fd);
756761
printfPQExpBuffer(&conn->errorMessage,
757762
libpq_gettext("could not read from file \"%s\": %s\n"),
758-
filename, pqStrerror(errno, sebuf, sizeof(sebuf)));
759-
lobjOid = InvalidOid;
763+
filename,
764+
pqStrerror(save_errno, sebuf, sizeof(sebuf)));
765+
return InvalidOid;
760766
}
761767

762768
(void) close(fd);
@@ -801,11 +807,15 @@ lo_export(PGconn *conn, Oid lobjId, const char *filename)
801807
*/
802808
fd = open(filename, O_CREAT | O_WRONLY | O_TRUNC | PG_BINARY, 0666);
803809
if (fd < 0)
804-
{ /* error */
810+
{
811+
/* We must do lo_close before setting the errorMessage */
812+
int save_errno = errno;
813+
814+
(void) lo_close(conn, lobj);
805815
printfPQExpBuffer(&conn->errorMessage,
806816
libpq_gettext("could not open file \"%s\": %s\n"),
807-
filename, pqStrerror(errno, sebuf, sizeof(sebuf)));
808-
(void) lo_close(conn, lobj);
817+
filename,
818+
pqStrerror(save_errno, sebuf, sizeof(sebuf)));
809819
return -1;
810820
}
811821

@@ -817,11 +827,15 @@ lo_export(PGconn *conn, Oid lobjId, const char *filename)
817827
tmp = write(fd, buf, nbytes);
818828
if (tmp != nbytes)
819829
{
820-
printfPQExpBuffer(&conn->errorMessage,
821-
libpq_gettext("could not write to file \"%s\": %s\n"),
822-
filename, pqStrerror(errno, sebuf, sizeof(sebuf)));
830+
/* We must do lo_close before setting the errorMessage */
831+
int save_errno = errno;
832+
823833
(void) lo_close(conn, lobj);
824834
(void) close(fd);
835+
printfPQExpBuffer(&conn->errorMessage,
836+
libpq_gettext("could not write to file \"%s\": %s\n"),
837+
filename,
838+
pqStrerror(save_errno, sebuf, sizeof(sebuf)));
825839
return -1;
826840
}
827841
}
@@ -839,7 +853,8 @@ lo_export(PGconn *conn, Oid lobjId, const char *filename)
839853
result = -1;
840854
}
841855

842-
if (close(fd))
856+
/* if we already failed, don't overwrite that msg with a close error */
857+
if (close(fd) && result >= 0)
843858
{
844859
printfPQExpBuffer(&conn->errorMessage,
845860
libpq_gettext("could not write to file \"%s\": %s\n"),

0 commit comments

Comments
 (0)