psql: Clean up more aggressively state of \bind[_named], \parse and \close

This fixes a couple of issues with the psql meta-commands mentioned
above when called repeatedly:
- The statement name is reset for each call.  If a command errors out,
its send_mode would still be set, causing an incorrect path to be taken
when processing a query.  For \bind_named, this could trigger an
assertion failure as a statement name is always expected for this
meta-command.  This issue has been introduced by d55322b0da60.
- The memory allocated for bind parameters can be leaked.  This is a bug
enlarged by d55322b0da60 that exists since 5b66de3433e2, as it is also
possible to leak memory with \bind in v16 and v17.  This requires a fix
that will be done on the affected branches separately.  This issue is
taken care of here for HEAD.

This patch tightens the cleanup of the state used for the extended
protocol meta-commands (bind parameters, send mode, statement name) by
doing it before running each meta-command on top of doing it once a
query has been processed, avoiding any leaks and the inconsistencies
when mixing calls, by refactoring the cleanup in a single routine used
in all the code paths where this step is required.

Reported-by: Alexander Lakhin
Author: Anthonin Bonnefoy
Discussion: https://postgr.es/m/2e5b89af-a351-ff0a-000c-037ac28314ab@gmail.com

diff --git a/src/bin/psql/command.c b/src/bin/psql/command.c
index 4dfc7b2d8577404a5f3646746970c38133e3c916..2bb87897505cea4d5bbc3012695fa647b4f15a9b 100644 (file)
--- a/src/bin/psql/command.c
+++ b/src/bin/psql/command.c
@@ -483,8 +483,7 @@ exec_command_bind(PsqlScanState scan_state, bool active_branch)
        int         nparams = 0;
        int         nalloc = 0;
 
-       pset.bind_params = NULL;
-       pset.stmtName = NULL;
+       clean_extended_state();
 
        while ((opt = psql_scan_slash_option(scan_state, OT_NORMAL, NULL, false)))
        {
@@ -521,8 +520,7 @@ exec_command_bind_named(PsqlScanState scan_state, bool active_branch,
        int         nparams = 0;
        int         nalloc = 0;
 
-       pset.bind_params = NULL;
-       pset.stmtName = NULL;
+       clean_extended_state();
 
        /* get the mandatory prepared statement name */
        opt = psql_scan_slash_option(scan_state, OT_NORMAL, NULL, false);
@@ -719,7 +717,8 @@ exec_command_close(PsqlScanState scan_state, bool active_branch, const char *cmd
        char       *opt = psql_scan_slash_option(scan_state,
                                                 OT_NORMAL, NULL, false);
 
-       pset.stmtName = NULL;
+       clean_extended_state();
+
        if (!opt)
        {
            pg_log_error("\\%s: missing required argument", cmd);
@@ -2205,7 +2204,8 @@ exec_command_parse(PsqlScanState scan_state, bool active_branch,
        char       *opt = psql_scan_slash_option(scan_state,
                                                 OT_NORMAL, NULL, false);
 
-       pset.stmtName = NULL;
+       clean_extended_state();
+
        if (!opt)
        {
            pg_log_error("\\%s: missing required argument", cmd);

diff --git a/src/bin/psql/common.c b/src/bin/psql/common.c
index 066dccbd8414aad0065a2357fb149ff314d46172..8a9211db41a68fbef01823fd1fa563d0c80b341e 100644 (file)
--- a/src/bin/psql/common.c
+++ b/src/bin/psql/common.c
@@ -1275,27 +1275,7 @@ sendquery_cleanup:
    }
 
    /* clean up after extended protocol queries */
-   switch (pset.send_mode)
-   {
-       case PSQL_SEND_EXTENDED_CLOSE:  /* \close */
-           free(pset.stmtName);
-           break;
-       case PSQL_SEND_EXTENDED_PARSE:  /* \parse */
-           free(pset.stmtName);
-           break;
-       case PSQL_SEND_EXTENDED_QUERY_PARAMS:   /* \bind */
-       case PSQL_SEND_EXTENDED_QUERY_PREPARED: /* \bind_named */
-           for (i = 0; i < pset.bind_nparams; i++)
-               free(pset.bind_params[i]);
-           free(pset.bind_params);
-           free(pset.stmtName);
-           pset.bind_params = NULL;
-           break;
-       case PSQL_SEND_QUERY:
-           break;
-   }
-   pset.stmtName = NULL;
-   pset.send_mode = PSQL_SEND_QUERY;
+   clean_extended_state();
 
    /* reset \gset trigger */
    if (pset.gset_prefix)
@@ -2287,6 +2267,43 @@ uri_prefix_length(const char *connstr)
    return 0;
 }
 
+/*
+ * Reset state related to extended query protocol
+ *
+ * Clean up any state related to bind parameters, statement name and
+ * PSQL_SEND_MODE.  This needs to be called after processing a query or when
+ * running a new meta-command that uses the extended query protocol, like
+ * \parse, \bind, etc.
+ */
+void
+clean_extended_state(void)
+{
+   int         i;
+
+   switch (pset.send_mode)
+   {
+       case PSQL_SEND_EXTENDED_CLOSE:  /* \close */
+           free(pset.stmtName);
+           break;
+       case PSQL_SEND_EXTENDED_PARSE:  /* \parse */
+           free(pset.stmtName);
+           break;
+       case PSQL_SEND_EXTENDED_QUERY_PARAMS:   /* \bind */
+       case PSQL_SEND_EXTENDED_QUERY_PREPARED: /* \bind_named */
+           for (i = 0; i < pset.bind_nparams; i++)
+               free(pset.bind_params[i]);
+           free(pset.bind_params);
+           free(pset.stmtName);
+           pset.bind_params = NULL;
+           break;
+       case PSQL_SEND_QUERY:
+           break;
+   }
+
+   pset.stmtName = NULL;
+   pset.send_mode = PSQL_SEND_QUERY;
+}
+
 /*
  * Recognized connection string either starts with a valid URI prefix or
  * contains a "=" in it.

diff --git a/src/bin/psql/common.h b/src/bin/psql/common.h
index 6efe12274fe593cf07cc209afbe9fbe74af62dcf..e3762a2c6c7c992266b970a0d5a71af096f56d41 100644 (file)
--- a/src/bin/psql/common.h
+++ b/src/bin/psql/common.h
@@ -41,6 +41,7 @@ extern bool standard_strings(void);
 extern const char *session_username(void);
 
 extern void expand_tilde(char **filename);
+extern void clean_extended_state(void);
 
 extern bool recognized_connection_string(const char *connstr);
 

diff --git a/src/test/regress/expected/psql.out b/src/test/regress/expected/psql.out
index 6aeb7cb96369233fc24ae79eb552855727bb45e5..cf040fbd8035905155a58edd8bf07ec2cffacd4c 100644 (file)
--- a/src/test/regress/expected/psql.out
+++ b/src/test/regress/expected/psql.out
@@ -132,6 +132,15 @@ SELECT $1, $2 \parse stmt3
  foo      | bar
 (1 row)
 
+-- Repeated calls.  The second call generates an error, cleaning up the
+-- statement name set by the first call.
+\bind_named stmt4
+\bind_named
+\bind_named: missing required argument
+\g
+ERROR:  there is no parameter $1
+LINE 1: SELECT $1, $2 
+               ^
 -- \close (extended query protocol)
 \close
 \close: missing required argument

diff --git a/src/test/regress/sql/psql.sql b/src/test/regress/sql/psql.sql
index 0a2f8b469226570301bfa53fd590bc4e4a1e4f33..8de90c805c067c1b1674e24e3d154e3d405719c4 100644 (file)
--- a/src/test/regress/sql/psql.sql
+++ b/src/test/regress/sql/psql.sql
@@ -58,6 +58,11 @@ SELECT $1, $2 \parse stmt3
 \bind_named stmt1 \g
 \bind_named stmt2 'foo' \g
 \bind_named stmt3 'foo' 'bar' \g
+-- Repeated calls.  The second call generates an error, cleaning up the
+-- statement name set by the first call.
+\bind_named stmt4
+\bind_named
+\g
 
 -- \close (extended query protocol)
 \close