From 39ff87324a6654a86b675690bd2dbbc49c272fc6 Mon Sep 17 00:00:00 2001
From: dengzhongyuan <dengzhongyuan@uniontech.com>
Date: Wed, 1 Jul 2026 14:44:13 +0800
Subject: [PATCH 1/2] trace: show error message when fork fails in TraceScreen

When TraceScreen_forkTracer() fails (e.g. out of memory, PID quota
exceeded), the trace screen now displays the system error message
instead of silently doing nothing.

Fixes #1991
---
 Action.c      |  6 ++----
 TraceScreen.c | 11 +++++++++++
 2 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/Action.c b/Action.c
index d630cb80d..88a7ce521 100644
--- a/Action.c
+++ b/Action.c
@@ -674,10 +674,8 @@ static Htop_Reaction actionStrace(State* st) {
    assert(Object_isA((const Object*) p, (const ObjectClass*) &Process_class));
 
    TraceScreen* ts = TraceScreen_new(p);
-   bool ok = TraceScreen_forkTracer(ts);
-   if (ok) {
-      InfoScreen_run((InfoScreen*)ts);
-   }
+   TraceScreen_forkTracer(ts);
+   InfoScreen_run((InfoScreen*)ts);
    TraceScreen_delete((Object*)ts);
    clear();
    CRT_enableDelay();
diff --git a/TraceScreen.c b/TraceScreen.c
index 42d5ee016..5b0ec661b 100644
--- a/TraceScreen.c
+++ b/TraceScreen.c
@@ -60,6 +60,16 @@ void TraceScreen_delete(Object* cast) {
    free(InfoScreen_done((InfoScreen*)this));
 }
 
+static void TraceScreen_scan(InfoScreen* super) {
+   TraceScreen* this = (TraceScreen*) super;
+   if (!this->strace_alive) {
+      char* err = NULL;
+      xAsprintf(&err, "%s", strerror(errno));
+      InfoScreen_addLine(super, err);
+      free(err);
+   }
+}
+
 static void TraceScreen_draw(InfoScreen* this) {
    InfoScreen_drawTitled(this, "Trace of process %d - %s", Process_getPid(this->process), Process_getCommand(this->process));
 }
@@ -209,6 +219,7 @@ const InfoScreenClass TraceScreen_class = {
       .extends = Class(Object),
       .delete = TraceScreen_delete
    },
+   .scan = TraceScreen_scan,
    .draw = TraceScreen_draw,
    .onErr = TraceScreen_updateTrace,
    .onKey = TraceScreen_onKey,

From 76e7f5d088b40efe08c325b09455aeb249bb9ba0 Mon Sep 17 00:00:00 2001
From: dengzhongyuan <dengzhongyuan@uniontech.com>
Date: Wed, 1 Jul 2026 14:56:34 +0800
Subject: [PATCH 2/2] trace: preserve errno across close() calls in error path

Save and restore errno in the TraceScreen_forkTracer error path so
that close() calls in the cleanup do not clobber the original error
value before it is read by TraceScreen_scan().
---
 TraceScreen.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/TraceScreen.c b/TraceScreen.c
index 5b0ec661b..87f99d01d 100644
--- a/TraceScreen.c
+++ b/TraceScreen.c
@@ -135,11 +135,14 @@ bool TraceScreen_forkTracer(TraceScreen* this) {
 
    return true;
 
-err:
+err: {
+   int saved_errno = errno;
    close(fdpair[1]);
    close(fdpair[0]);
+   errno = saved_errno;
    return false;
 }
+}
 
 static void TraceScreen_updateTrace(InfoScreen* super) {
    TraceScreen* this = (TraceScreen*) super;