From 1f5f40c091a3e91626fc39ba31d7407cbae9aa4d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Christian=20G=C3=B6ttsche?= <cgzones@googlemail.com>
Date: Sun, 16 May 2021 19:55:31 +0200
Subject: [PATCH] Print current settings on crash

---
 CRT.c         |  8 ++++++++
 CommandLine.c |  6 ++++--
 Settings.c    | 24 +++++++++++++++++-------
 Settings.h    |  2 +-
 4 files changed, 30 insertions(+), 10 deletions(-)

diff --git a/CRT.c b/CRT.c
index 481e16c1..1f0a0b28 100644
--- a/CRT.c
+++ b/CRT.c
@@ -80,6 +80,7 @@ bool CRT_utf8 = false;
 
 const char* const* CRT_treeStr = CRT_treeStrAscii;
 
+static const Settings* CRT_crashSettings;
 static const int* CRT_delay;
 
 const char* CRT_degreeSign;
@@ -767,6 +768,7 @@ void CRT_init(const Settings* settings, bool allowUnicode) {
 
    initscr();
    noecho();
+   CRT_crashSettings = settings;
    CRT_delay = &(settings->delay);
    CRT_colors = CRT_colorSchemes[settings->colorScheme];
    CRT_colorScheme = settings->colorScheme;
@@ -953,6 +955,12 @@ void CRT_handleSIGSEGV(int signal) {
       signal, signal_str
    );
 
+   fprintf(stderr,
+      "Setting information:\n"
+      "--------------------\n");
+   Settings_write(CRT_crashSettings, true);
+   fprintf(stderr, "\n");
+
 #ifdef HAVE_EXECINFO_H
    fprintf(stderr,
       "Backtrace information:\n"
diff --git a/CommandLine.c b/CommandLine.c
index 16ded1fa..60582dcf 100644
--- a/CommandLine.c
+++ b/CommandLine.c
@@ -361,7 +361,7 @@ int CommandLine_run(const char* name, int argc, char** argv) {
    CRT_done();
 
    if (settings->changed) {
-      int r = Settings_write(settings);
+      int r = Settings_write(settings, false);
       if (r < 0)
          fprintf(stderr, "Can not save configuration to %s: %s\n", settings->filename, strerror(-r));
    }
@@ -373,10 +373,12 @@ int CommandLine_run(const char* name, int argc, char** argv) {
    MetersPanel_cleanup();
 
    UsersTable_delete(ut);
-   Settings_delete(settings);
 
    if (flags.pidMatchList)
       Hashtable_delete(flags.pidMatchList);
 
+   /* Delete Settings last, since it can get accessed in the crash handler */
+   Settings_delete(settings);
+
    return 0;
 }
diff --git a/Settings.c b/Settings.c
index 0606df30..92d96dd5 100644
--- a/Settings.c
+++ b/Settings.c
@@ -281,13 +281,20 @@ static void writeMeterModes(const Settings* this, FILE* fd, int column) {
    fprintf(fd, "\n");
 }
 
-int Settings_write(const Settings* this) {
-   FILE* fd = fopen(this->filename, "w");
-   if (fd == NULL)
-      return -errno;
+int Settings_write(const Settings* this, bool onCrash) {
+   FILE* fd;
+   if (onCrash) {
+      fd = stderr;
+   } else {
+      fd = fopen(this->filename, "w");
+      if (fd == NULL)
+         return -errno;
+   }
 
-   fprintf(fd, "# Beware! This file is rewritten by htop when settings are changed in the interface.\n");
-   fprintf(fd, "# The parser is also very primitive, and not human-friendly.\n");
+   if (!onCrash) {
+      fprintf(fd, "# Beware! This file is rewritten by htop when settings are changed in the interface.\n");
+      fprintf(fd, "# The parser is also very primitive, and not human-friendly.\n");
+   }
    writeFields(fd, this->fields, "fields");
    // This "-1" is for compatibility with the older enum format.
    fprintf(fd, "sort_key=%d\n", (int) this->sortKey - 1);
@@ -333,6 +340,9 @@ int Settings_write(const Settings* this) {
    fprintf(fd, "topology_affinity=%d\n", (int) this->topologyAffinity);
    #endif
 
+   if (onCrash)
+      return 0;
+
    int r = 0;
 
    if (ferror(fd) != 0)
@@ -431,7 +441,7 @@ Settings* Settings_new(unsigned int initialCpuCount) {
       ok = Settings_read(this, legacyDotfile, initialCpuCount);
       if (ok) {
          // Transition to new location and delete old configuration file
-         if (Settings_write(this) == 0) {
+         if (Settings_write(this, false) == 0) {
             unlink(legacyDotfile);
          }
       }
diff --git a/Settings.h b/Settings.h
index 7313ce38..fb621adb 100644
--- a/Settings.h
+++ b/Settings.h
@@ -87,7 +87,7 @@ static inline int Settings_getActiveDirection(const Settings* this) {
 
 void Settings_delete(Settings* this);
 
-int Settings_write(const Settings* this);
+int Settings_write(const Settings* this, bool onCrash);
 
 Settings* Settings_new(unsigned int initialCpuCount);