postgres.git / summary / log / commit / refs

commit    6f9ee74d45aa7c1836b6c12b6e2a958327c16ab5
Author:   Michael Paquier <michael@paquier.xyz>
Date:     Thu Mar 16 00:32:36 2023 +0000
First released in: 16.0

    Improve handling of psql \watch's interval argument
    
    A failure in parsing the interval value defined in the \watch command
    was silently switched to 1s of interval between two queries, which can
    be confusing.  This commit improves the error handling, and a couple of
    tests are added to check after:
    - An incorrect value.
    - An out-of-range value.
    - A negative value.
    
    A value of zero is able to work now, meaning that there is no interval
    of time between two queries in a \watch loop.  No backpatch is done, as
    it could break existing applications.
    
    Author: Andrey Borodin
    Reviewed-by: Kyotaro Horiguchi, Nathan Bossart, Michael Paquier
    Discussion: https://postgr.es/m/CAAhFRxiZ2-n_L1ErMm9AZjgmUK=qS6VHb+0SaMn8sqqbhF7How@mail.gmail.com


 src/bin/psql/command.c      | 18 +++++++++++++++---
 src/bin/psql/t/001_basic.pl | 17 +++++++++++++++++
 2 files changed, 32 insertions(+), 3 deletions(-)

diff --git a/src/bin/psql/command.c b/src/bin/psql/command.c
index 955397ee9dc..61ec049f054 100644
--- a/src/bin/psql/command.c
+++ b/src/bin/psql/command.c
@@ -2776,9 +2776,18 @@ exec_command_watch(PsqlScanState scan_state, bool active_branch,
 		/* Convert optional sleep-length argument */
 		if (opt)
 		{
-			sleep = strtod(opt, NULL);
-			if (sleep <= 0)
-				sleep = 1;
+			char	   *opt_end;
+
+			errno = 0;
+			sleep = strtod(opt, &opt_end);
+			if (sleep < 0 || *opt_end || errno == ERANGE)
+			{
+				pg_log_error("\\watch: incorrect interval value '%s'", opt);
+				free(opt);
+				resetPQExpBuffer(query_buf);
+				psql_scan_reset(scan_state);
+				return PSQL_CMD_ERROR;
+			}
 			free(opt);
 		}
 
@@ -5183,6 +5192,9 @@ do_watch(PQExpBuffer query_buf, double sleep)
 		if (pagerpipe && ferror(pagerpipe))
 			break;
 
+		if (sleep == 0)
+			continue;
+
 #ifdef WIN32
 
 		/*
diff --git a/src/bin/psql/t/001_basic.pl b/src/bin/psql/t/001_basic.pl
index 0f394420b26..64ce0120621 100644
--- a/src/bin/psql/t/001_basic.pl
+++ b/src/bin/psql/t/001_basic.pl
@@ -350,4 +350,21 @@ psql_like(
 	'\copy from with DEFAULT'
 );
 
+# Check \watch errors
+psql_fails_like(
+	$node,
+	'SELECT 1;\watch -10',
+	qr/incorrect interval value '-10'/,
+	'\watch, negative interval');
+psql_fails_like(
+	$node,
+	'SELECT 1;\watch 10ab',
+	qr/incorrect interval value '10ab'/,
+	'\watch incorrect interval');
+psql_fails_like(
+	$node,
+	'SELECT 1;\watch 10e400',
+	qr/incorrect interval value '10e400'/,
+	'\watch out-of-range interval');
+
 done_testing();


[parent: dccb4d1c0391]