main: Fix subcommand usage output

This commit sets prgname correctly so that the "ostree subcommand
--help" output prints the subcommand rather than just "ostree".

This was removed in commit f0519e541f because it tripped the thread
sanitizer, but it's being added back conditionally so most users who
don't compile with -fsanitize=adress see proper help output.

Closes: #1054
Approved by: cgwalters

configure.ac

@@ -58,6 +58,19 @@ else
   AC_MSG_RESULT([no])
 fi
 AM_CONDITIONAL(BUILDOPT_ASAN, [test x$using_asan = xyes])
+AM_COND_IF([BUILDOPT_ASAN],
+  [AC_DEFINE([BUILDOPT_ASAN], 1, [Define if we are building with -fsanitize=address])])
+
+AC_MSG_CHECKING([for -fsanitize=thread in CFLAGS])
+if echo $CFLAGS | grep -q -e -fsanitize=thread; then
+  AC_MSG_RESULT([yes])
+  using_tsan=yes
+else
+  AC_MSG_RESULT([no])
+fi
+AM_CONDITIONAL(BUILDOPT_TSAN, [test x$using_tsan = xyes])
+AM_COND_IF([BUILDOPT_TSAN],
+  [AC_DEFINE([BUILDOPT_TSAN], 1, [Define if we are building with -fsanitize=thread])])
 
 # Initialize libtool
 LT_PREREQ([2.2.4])

src/ostree/ot-main.c

@@ -117,6 +117,9 @@ ostree_run (int    argc,
   OstreeCommand *command;
   GError *error = NULL;
   GCancellable *cancellable = NULL;
+#ifndef BUILDOPT_TSAN
+  g_autofree char *prgname = NULL;
+#endif
   const char *command_name = NULL;
   gboolean success = FALSE;
   int in, out;
@@ -192,6 +195,11 @@ ostree_run (int    argc,
       goto out;
     }
 
+#ifndef BUILDOPT_TSAN
+  prgname = g_strdup_printf ("%s %s", g_get_prgname (), command_name);
+  g_set_prgname (prgname);
+#endif
+
   if (!command->fn (argc, argv, cancellable, &error))
     goto out;