Start a login shell in the home directory when launched from the desktop

lib/shitty/application.cpp

@@ -603,6 +603,7 @@ int ApplicationImpl::run(int argc, char* argv[]) {
     // window, and setenv() must never run in a forked child of a
     // multithreaded process: glibc's environ lock is not reset at fork.
     configureTerminalChildEnvironment(*composer.brand, composer.opts->vt.widths);
+    enterHomeWhenLaunchedFromDesktop();
     composer.fontSize = composer.opts->fontsize;
     composer.inputRemap = InputRemap::create(composer);
     if (testFd >= 0) {

lib/shitty/options.cpp

@@ -19,6 +19,7 @@
 #include "toml.h"
 #include "brand.h"
 #include "darts.h"
+#include "startup.h"
 #include "terminal_colors.h"
 
 #include <lib/vterm/num.h>
@@ -38,6 +39,7 @@
 #include <wchar.h>
 #include <stdlib.h>
 #include <string.h>
+#include <unistd.h>
 
 using namespace stl;
 
@@ -1272,7 +1274,13 @@ void OptionsParser::parse() {
         vt.boldColors = getBool("boldColors");
         vt.kittyCtrlBaseLayout = getBool("kittyCtrlBaseLayout");
         noDecorations = getBool("no-decorations");
-        login = getBool("login");
+        // A desktop launch has no shell environment to inherit, so the
+        // profile files that build PATH (Homebrew's lives in .zprofile) only
+        // run for a login shell. An explicit login setting still wins.
+        StringView loginOption;
+        OptionSource loginSource = OptionSource::NONE;
+        get("login", loginOption, &loginSource);
+        login = getBool("login") || (loginSource == OptionSource::HardDefault && launchedFromDesktop(getppid()));
         maximized = getBool("maximized");
         fullscreen = getBool("fullscreen");
         showWraps = getBool("showWraps");

lib/shitty/startup.cpp

@@ -11,6 +11,8 @@
 #include <lib/vterm/fatal.h>
 #include <lib/vterm/term_features.h>
 
+#include <std/ios/sys.h>
+
 #include <pwd.h>
 #include <limits.h>
 #include <stdlib.h>
@@ -149,3 +151,33 @@ void configureTerminalChildEnvironment(const Brand& brand, const UnicodeWidths&
     }
     brand.configureVersionEnvironment();
 }
+
+bool launchedFromDesktop(pid_t parent) {
+#if defined(__APPLE__)
+    return parent == 1;
+#else
+    (void)(parent);
+    return false;
+#endif
+}
+
+void enterHomeWhenLaunchedFromDesktop() {
+    if (!launchedFromDesktop(getppid())) {
+        return;
+    }
+    char current[PATH_MAX];
+    if (getcwd(current, sizeof(current)) == nullptr || StringView(current) != StringView(u8"/")) {
+        return;
+    }
+    const char* home = getenv("HOME");
+    if (home == nullptr || home[0] != '/') {
+        const passwd* entry = getpwuid(getuid());
+        home = entry != nullptr ? entry->pw_dir : nullptr;
+    }
+    if (home == nullptr || home[0] != '/') {
+        return;
+    }
+    if (chdir(home) < 0) {
+        sysO << StringView(u8"Warning: could not enter the home directory.") << endL;
+    }
+}

lib/shitty/startup.h

@@ -11,6 +11,8 @@
 #include <std/lib/vector.h>
 #include <std/sys/types.h>
 
+#include <sys/types.h>
+
 struct Brand;
 class UnicodeWidths;
 
@@ -30,3 +32,11 @@ struct LaunchCommand {
 LaunchCommand buildLaunchCommand(int argc, char* argv[], stl::StringView defaultShell, bool login);
 
 void configureTerminalChildEnvironment(const Brand& brand, const UnicodeWidths& widths);
+
+// True when launchd itself started this process - a Finder, Dock or open(1)
+// launch of the .app on macOS - so no shell handed it an environment.
+// parent is the parent process id; always false outside macOS.
+bool launchedFromDesktop(pid_t parent);
+
+// A desktop launch starts in "/", which is no place for a shell to begin.
+void enterHomeWhenLaunchedFromDesktop();

lib/shitty/startup_ut.cpp

@@ -85,4 +85,14 @@ STD_TEST_SUITE(Startup) {
         // The width level lands in the reported features verbatim.
         STD_INSIST(StringView(getenv("TERM_FEATURES")) == StringView("T3CwLrMSc7UUw15Ts3BFGsGoSyHNoSxP"));
     }
+
+    STD_TEST(OnlyLaunchdAsParentMeansADesktopLaunch) {
+        STD_INSIST(!launchedFromDesktop(2));
+        STD_INSIST(!launchedFromDesktop(4711));
+#if defined(__APPLE__)
+        STD_INSIST(launchedFromDesktop(1));
+#else
+        STD_INSIST(!launchedFromDesktop(1));
+#endif
+    }
 }