A pane can potentially have up to INT_MAX lines of history (limited
via "history-limit"), but "capture-pane" only accepts values down to
SHRT_MIN for its "-E" and "-S" options.
To allow it to capture a pane's full history, negative numbers down
to at least -INT_MAX should be accepted for these options. Technical
users might try to use INT_MIN, so we should accept that too.
Ideally, we should use MIN(INT_MIN, -INT_MAX), but INT_MIN is less
than -INT_MAX on most platforms, so it should suffice.
The existing code already handles "below zero" unsigned overflow
situations.
The upper bound on the specified line number remains unchanged at
SHRT_MAX. Technically, a pane's height (gd->sy) could possibly be up
to USHRT_MAX (from TIOCGWINSZ, winsize.ws_row is usually "unsigned
short" or "new-session -dy N", where N is limited to USHRT_MAX), but
allowing line specifications that high would open up the possibility
of integer overflow on a platform where USHRT_MAX equals UINT_MAX.
Realistically, it seems highly unlikely that any terminal emulators
allow heights even close to the smallest conforming SHRT_MAX (much
less USHRT_MAX, whether it equals UINT_MAX or not), so SHRT_MAX is
probably an acceptable upper limit.
---
I found this issue while attempting to capture all of a pane's
history and its currently displayed lines (generically, without
knowledge of the pane's effective hlimit), by trying to use -1000000
as a sufficiently large, negative value with "-S". The result was
that that it only captured the displayed lines (the default, since
strtonum reported ERANGE). I had to back down to -32768 to make it
work.
I am not sure how many users ever actually put "history-limit"
anywhere between SHRT_MAX and INT_MAX, but it seemed like a minor
bug not to support such configurations.
---
trunk/cmd-capture-pane.c | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/trunk/cmd-capture-pane.c b/trunk/cmd-capture-pane.c
index 9f2d792..52fc792 100644
--- a/trunk/cmd-capture-pane.c
+++ b/trunk/cmd-capture-pane.c
@@ -59,7 +59,7 @@ cmd_capture_pane_exec(struct cmd *self, struct cmd_ctx *ctx)
buf = NULL;
len = 0;
- n = args_strtonum(args, 'S', SHRT_MIN, SHRT_MAX, &cause);
+ n = args_strtonum(args, 'S', INT_MIN, SHRT_MAX, &cause);
if (cause != NULL) {
top = gd->hsize;
xfree(cause);
@@ -70,7 +70,7 @@ cmd_capture_pane_exec(struct cmd *self, struct cmd_ctx *ctx)
if (top > gd->hsize + gd->sy - 1)
top = gd->hsize + gd->sy - 1;
- n = args_strtonum(args, 'E', SHRT_MIN, SHRT_MAX, &cause);
+ n = args_strtonum(args, 'E', INT_MIN, SHRT_MAX, &cause);
if (cause != NULL) {
bottom = gd->hsize + gd->sy - 1;
xfree(cause);
--
1.7.7.4
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