From 101d6ae755656b675b7c18db655249511982b780 Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Sat, 2 Feb 2013 14:21:24 -0500 Subject: [PATCH] Prevent "\g filename" from affecting subsequent commands after an error. In the previous coding, psql's state variable saying that output should go to a file was only reset after successful completion of a query returning tuples. Thus for example, regression=# select 1/0 regression-# \g somefile ERROR: division by zero regression=# select 1/2; regression=# ... huh, I wonder where that output went. Even more oddly, the state was not reset even if it's the file that's causing the failure: regression=# select 1/2 \g /foo /foo: Permission denied regression=# select 1/2; /foo: Permission denied regression=# select 1/2; /foo: Permission denied This seems to me not to satisfy the principle of least surprise. \g is certainly not documented in a way that suggests its effects are at all persistent. To fix, adjust the code so that the flag is reset at exit from SendQuery no matter what happened. Noted while reviewing the \gset patch, which had comparable issues. Arguably this is a bug fix, but I'll refrain from back-patching for now. --- doc/src/sgml/ref/psql-ref.sgml | 10 +++++++--- src/bin/psql/command.c | 2 +- src/bin/psql/common.c | 32 +++++++++++++++++++------------- 3 files changed, 27 insertions(+), 17 deletions(-) diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml index 4c87d8ad7f..eb5e3b1904 100644 --- a/doc/src/sgml/ref/psql-ref.sgml +++ b/doc/src/sgml/ref/psql-ref.sgml @@ -1608,9 +1608,13 @@ Tue Oct 26 21:40:57 CEST 1999 optionally stores the query's output in filename or pipes the output into a separate Unix shell executing command. A bare - \g is virtually equivalent to a semicolon. A - \g with argument is a one-shot + class="parameter">command. The file or command is + written to only if the query successfully returns zero or more tuples, + not if the query fails or is a non-data-returning SQL command. + + + A bare \g is essentially equivalent to a semicolon. + A \g with argument is a one-shot alternative to the \o command. diff --git a/src/bin/psql/command.c b/src/bin/psql/command.c index 20c45e2d0a..1e9aa89089 100644 --- a/src/bin/psql/command.c +++ b/src/bin/psql/command.c @@ -731,7 +731,7 @@ exec_command(const char *cmd, free(fname); } - /* \g means send query */ + /* \g [filename] means send query, optionally with output to file/pipe */ else if (strcmp(cmd, "g") == 0) { char *fname = psql_scan_slash_option(scan_state, diff --git a/src/bin/psql/common.c b/src/bin/psql/common.c index 5fb031650e..ab517906fc 100644 --- a/src/bin/psql/common.c +++ b/src/bin/psql/common.c @@ -607,9 +607,6 @@ PrintQueryTuples(const PGresult *results) pset.queryFout = queryFout_copy; pset.queryFoutPipe = queryFoutPipe_copy; - - free(pset.gfname); - pset.gfname = NULL; } else printQuery(results, &my_popt, pset.queryFout, pset.logfile); @@ -835,14 +832,14 @@ SendQuery(const char *query) PGresult *results; PGTransactionStatusType transaction_status; double elapsed_msec = 0; - bool OK, - on_error_rollback_savepoint = false; + bool OK = false; + bool on_error_rollback_savepoint = false; static bool on_error_rollback_warning = false; if (!pset.db) { psql_error("You are currently not connected to a database.\n"); - return false; + goto sendquery_cleanup; } if (pset.singlestep) @@ -856,7 +853,7 @@ SendQuery(const char *query) fflush(stdout); if (fgets(buf, sizeof(buf), stdin) != NULL) if (buf[0] == 'x') - return false; + goto sendquery_cleanup; } else if (pset.echo == PSQL_ECHO_QUERIES) { @@ -887,7 +884,7 @@ SendQuery(const char *query) psql_error("%s", PQerrorMessage(pset.db)); PQclear(results); ResetCancelConn(); - return false; + goto sendquery_cleanup; } PQclear(results); transaction_status = PQtransactionStatus(pset.db); @@ -912,7 +909,7 @@ SendQuery(const char *query) psql_error("%s", PQerrorMessage(pset.db)); PQclear(results); ResetCancelConn(); - return false; + goto sendquery_cleanup; } PQclear(results); on_error_rollback_savepoint = true; @@ -1008,10 +1005,11 @@ SendQuery(const char *query) { psql_error("%s", PQerrorMessage(pset.db)); PQclear(svptres); + OK = false; PQclear(results); ResetCancelConn(); - return false; + goto sendquery_cleanup; } PQclear(svptres); } @@ -1037,6 +1035,17 @@ SendQuery(const char *query) PrintNotifications(); + /* perform cleanup that should occur after any attempted query */ + +sendquery_cleanup: + + /* reset \g's output-to-filename trigger */ + if (pset.gfname) + { + free(pset.gfname); + pset.gfname = NULL; + } + return OK; } @@ -1218,9 +1227,6 @@ ExecQueryUsingCursor(const char *query, double *elapsed_msec) pset.queryFout = queryFout_copy; pset.queryFoutPipe = queryFoutPipe_copy; - - free(pset.gfname); - pset.gfname = NULL; } else if (did_pager) {