From ef96a6614bb816e8dd1f1bf594b019c73384dda3 Mon Sep 17 00:00:00 2001
From: Fabian Homborg <FHomborg@gmail.com>
Date: Wed, 14 Apr 2021 17:17:22 +0200
Subject: [PATCH] Update termsize before a sigwinch handler

This could have been one iteration off, e.g.

```fish
function on-winch --on-signal winch
    echo $LINES
end
```

Resize the terminal, it'll print e.g.

24

then run `echo $LINES` interactively, it might have a different answer.

This isn't beautiful, but it works. A better solution might be to make
the termsize vars electric and just always update them on read?
---
 src/event.cpp              |  7 +++++++
 tests/pexpects/terminal.py | 14 ++++++++++++++
 2 files changed, 21 insertions(+)

diff --git a/src/event.cpp b/src/event.cpp
index bb96898f6..040a5c3b2 100644
--- a/src/event.cpp
+++ b/src/event.cpp
@@ -21,6 +21,7 @@
 #include "parser.h"
 #include "proc.h"
 #include "signal.h"
+#include "termsize.h"
 #include "wutil.h"  // IWYU pragma: keep
 
 class pending_signals_t {
@@ -327,6 +328,12 @@ void event_fire_delayed(parser_t &parser) {
     if (signals.any()) {
         for (uint32_t sig = 0; sig < signals.size(); sig++) {
             if (signals.test(sig)) {
+                // HACK: The only variables we change in response to a *signal*
+                // are $COLUMNS and $LINES.
+                // Do that now.
+                if (sig == SIGWINCH) {
+                    (void)termsize_container_t::shared().updating(parser);
+                }
                 auto e = std::make_shared<event_t>(event_type_t::signal);
                 e->desc.param1.signal = sig;
                 e->arguments.push_back(sig2wcs(sig));
diff --git a/tests/pexpects/terminal.py b/tests/pexpects/terminal.py
index 37a3592e8..3ffa10f20 100644
--- a/tests/pexpects/terminal.py
+++ b/tests/pexpects/terminal.py
@@ -21,6 +21,19 @@ expect_str("term-support: Terminal has 0 columns, falling back to default width"
 expect_str("term-support: Terminal has 0 rows, falling back to default height")
 expect_prompt()
 
+# See if $LINES/$COLUMNS change in response to sigwinch, also in a --on-signal function
+sendline("function on-winch --on-signal winch; echo $LINES $COLUMNS; end")
+expect_prompt()
+sp.spawn.setwinsize(40, 50)
+expect_str("40 50")
+sendline("echo $LINES $COLUMNS")
+expect_prompt("40 50")
+
+sp.spawn.setwinsize(20, 70)
+expect_str("20 70")
+sendline("echo $LINES $COLUMNS")
+expect_prompt("20 70")
+
 sendline("stty -a")
 expect_prompt()
 # Confirm flow control in the shell is disabled - we should ignore the ctrl-s in there.
@@ -48,3 +61,4 @@ if platform.system() in ["Linux"]:
     expect_str("hellohello", timeout=1, shouldfail=True)
     send("\x11") # ctrl-q to resume flow
     expect_prompt("hellohello")
+