Remove dead code from display subcommand handler

The display subcommand was set up to be intercepted when given the help
flag, so the code to call the internal binary only ran when calling it
with no further arguments. Given that the internal binary's help message
and the subcommand's are nearly identical it's better to always print
its own help without deferring to the internal one.

Author: jemoreira

base/cvd/cuttlefish/host/commands/cvd/cli/commands/BUILD.bazel

@@ -92,11 +92,9 @@ cf_cc_library(
     srcs = ["display.cpp"],
     hdrs = ["display.h"],
     deps = [
-        "//cuttlefish/common/libs/utils:contains",
         "//cuttlefish/common/libs/utils:files",
         "//cuttlefish/common/libs/utils:flag_parser",
         "//cuttlefish/common/libs/utils:subprocess",
-        "//cuttlefish/common/libs/utils:users",
         "//cuttlefish/host/commands/cvd/cli:command_request",
         "//cuttlefish/host/commands/cvd/cli:types",
         "//cuttlefish/host/commands/cvd/cli:utils",

base/cvd/cuttlefish/host/commands/cvd/cli/commands/display.cpp

@@ -28,11 +28,9 @@
 
 #include "absl/strings/str_cat.h"
 
-#include "cuttlefish/common/libs/utils/contains.h"
 #include "cuttlefish/common/libs/utils/files.h"
 #include "cuttlefish/common/libs/utils/flag_parser.h"
 #include "cuttlefish/common/libs/utils/subprocess.h"
-#include "cuttlefish/common/libs/utils/users.h"
 #include "cuttlefish/host/commands/cvd/cli/command_request.h"
 #include "cuttlefish/host/commands/cvd/cli/commands/command_handler.h"
 #include "cuttlefish/host/commands/cvd/cli/selector/selector.h"
@@ -71,12 +69,14 @@ class CvdDisplayCommandHandler : public CvdCommandHandler {
     const cvd_common::Envs& env = request.Env();
 
     std::vector<std::string> subcmd_args = request.SubcommandArguments();
+    if (subcmd_args.empty()) {
+      // Also print help when given no arguments
+      std::cerr << kDetailedHelpText;
+      return {};
+    }
 
-    bool is_help = CF_EXPECT(IsHelp(subcmd_args));
     // may modify subcmd_args by consuming in parsing
-    Command command =
-        is_help ? CF_EXPECT(HelpCommand(request, subcmd_args, env))
-                : CF_EXPECT(NonHelpCommand(request, subcmd_args, env));
+    Command command = CF_EXPECT(BuildCommand(request, subcmd_args, env));
 
     siginfo_t infop;  // NOLINT(misc-include-cleaner)
     command.Start().Wait(&infop, WEXITED);
@@ -98,30 +98,9 @@ class CvdDisplayCommandHandler : public CvdCommandHandler {
   }
 
  private:
-  Result<Command> HelpCommand(const CommandRequest& request,
-                              const cvd_common::Args& subcmd_args,
-                              cvd_common::Envs envs) {
-    const std::string android_host_out = CF_EXPECT(AndroidHostPath(envs));
-    const std::string cvd_display_bin_path =
-        absl::StrCat(android_host_out, "/bin/", kDisplayBin);
-    std::string home = Contains(envs, "HOME") ? envs.at("HOME")
-                                              : CF_EXPECT(SystemWideUserHome());
-    envs["HOME"] = home;
-    envs[kAndroidHostOut] = android_host_out;
-    envs[kAndroidSoongHostOut] = android_host_out;
-    ConstructCommandParam construct_cmd_param{.bin_path = cvd_display_bin_path,
-                                              .home = home,
-                                              .args = subcmd_args,
-                                              .envs = std::move(envs),
-                                              .working_dir = CurrentDirectory(),
-                                              .command_name = kDisplayBin};
-    Command command = CF_EXPECT(ConstructCommand(construct_cmd_param));
-    return command;
-  }
-
-  Result<Command> NonHelpCommand(const CommandRequest& request,
-                                 cvd_common::Args& subcmd_args,
-                                 cvd_common::Envs envs) {
+  Result<Command> BuildCommand(const CommandRequest& request,
+                               cvd_common::Args& subcmd_args,
+                               cvd_common::Envs envs) {
     // test if there is --instance_num flag
     int instance_num = -1;
     Flag instance_num_flag = GflagsCompatFlag("instance_num", instance_num);
@@ -163,15 +142,6 @@ class CvdDisplayCommandHandler : public CvdCommandHandler {
     return command;
   }
 
-  Result<bool> IsHelp(const cvd_common::Args& cmd_args) const {
-    // cvd display --help, --helpxml, etc or simply cvd display
-    if (cmd_args.empty() || CF_EXPECT(HasHelpFlag(cmd_args))) {
-      return true;
-    }
-    // cvd display help <subcommand> format
-    return (cmd_args.front() == "help");
-  }
-
   InstanceManager& instance_manager_;
   static constexpr char kDisplayBin[] = "cvd_internal_display";
 };