From 111d19818a4a7c96c87e330c6c143fa03bb86819 Mon Sep 17 00:00:00 2001 From: Tom Tromey Date: Sat, 8 Jan 2022 19:37:38 -0700 Subject: [PATCH] Handle "set height 1" PR cli/17151 points out that "set height 1" has pathological behavior in gdb. What I see is that gdb will endlessly print the pagination prompt. This patch takes a simple and expedient approach to a fix: pretend that the height is really 2. Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=17151 --- gdb/testsuite/gdb.base/page.exp | 7 ++++--- gdb/utils.c | 10 ++++++++-- 2 files changed, 12 insertions(+), 5 deletions(-) diff --git a/gdb/testsuite/gdb.base/page.exp b/gdb/testsuite/gdb.base/page.exp index a38f1dd0c94..268777f8acb 100644 --- a/gdb/testsuite/gdb.base/page.exp +++ b/gdb/testsuite/gdb.base/page.exp @@ -121,6 +121,7 @@ foreach_with_prefix size {"0" "0x80000000" "unlimited"} { gdb_test "set width -1" "integer -1 out of range" gdb_test "set height -1" "integer -1 out of range" -gdb_exit -return 0 - +# A height of 1 used to cause pathological behavior -- it would +# endlessly prompt for paging without printing anything. +gdb_test_no_output "set height 1" +gdb_test "print 23" " = 23" diff --git a/gdb/utils.c b/gdb/utils.c index b7d5859d6b3..2465bf3a3ed 100644 --- a/gdb/utils.c +++ b/gdb/utils.c @@ -1601,6 +1601,12 @@ pager_file::puts (const char *linebuffer) m_wrap_indent = 0; }); + /* If the user does "set height 1" then the pager will exhibit weird + behavior. This is pathological, though, so don't allow it. */ + const unsigned int lines_allowed = (lines_per_page > 1 + ? lines_per_page - 1 + : 1); + /* Go through and output each character. Show line extension when this is necessary; prompt user for new page when this is necessary. */ @@ -1613,7 +1619,7 @@ pager_file::puts (const char *linebuffer) it here. */ if (pagination_enabled && !pagination_disabled_for_command - && lines_printed >= lines_per_page - 1) + && lines_printed >= lines_allowed) prompt_for_continue (); while (*lineptr && *lineptr != '\n') @@ -1690,7 +1696,7 @@ pager_file::puts (const char *linebuffer) this loop, so we must continue to check it here. */ if (pagination_enabled && !pagination_disabled_for_command - && lines_printed >= lines_per_page - 1) + && lines_printed >= lines_allowed) { prompt_for_continue (); did_paginate = true; -- 2.30.2