Clean up initialization code for programs.

Make the init_progfile_dir() call unconditionally, even if plugins
aren't supported, as that doesn't necessarily mean nobody uses the
directory containing the executable.

Report the error the same way in all programs, and free the error string
after we're finished with it.

Make the error - and the comment before the code - reflect what
init_progfile_dir() is actually doing (the goal is to get the full
pathname of the directory *containing* the executable; that's generally
done by getting the pathname of the executable and stripping off the
name of the executable, but that's won't necessarily always be the
case).  Also note for TShark that we won't be able to capture traffic,
just as we do for Wireshark (if we don't have the pathname of the
program file, we don't have a pathname to use to find dumpcap).

Have the plugin scanner just fail silently if we weren't able to get the
plugin directory path, so we don't have to worry about calling it if
init_progfile_dir() fails.

Clean up white space while we're at it.

Change-Id: I8e580c719aab6fbf74a764bf6629962394fff7c8
Reviewed-on: https://code.wireshark.org/review/19076
Reviewed-by: Guy Harris <guy@alum.mit.edu>

13 files changed, 168 insertions, 126 deletions

diff --git a/capinfos.c b/capinfos.c
index d1773113b4..a6539cc672 100644
--- a/capinfos.c
+++ b/capinfos.c
@@ -1405,6 +1405,7 @@ main(int argc, char *argv[])
 {
   GString *comp_info_str;
   GString *runtime_info_str;
+  char  *init_progfile_dir_error;
   wtap  *wth;
   int    err;
   gchar *err_info;
@@ -1417,9 +1418,6 @@ main(int argc, char *argv[])
   };
 
   int status = 0;
-#ifdef HAVE_PLUGINS
-  char  *init_progfile_dir_error;
-#endif
 #ifdef HAVE_LIBGCRYPT
   FILE  *fh;
   char  *hash_buf = NULL;
@@ -1459,26 +1457,33 @@ main(int argc, char *argv[])
    */
   init_process_policies();
 
+  /*
+   * Attempt to get the pathname of the directory containing the
+   * executable file.
+   */
+  init_progfile_dir_error = init_progfile_dir(argv[0], main);
+  if (init_progfile_dir_error != NULL) {
+    fprintf(stderr,
+            "capinfos: Can't get pathname of directory containing the capinfos program: %s.\n",
+            init_progfile_dir_error);
+    g_free(init_progfile_dir_error);
+  }
+
   wtap_init();
 
 #ifdef HAVE_PLUGINS
-  if ((init_progfile_dir_error = init_progfile_dir(argv[0], main))) {
-    g_warning("capinfos: init_progfile_dir(): %s", init_progfile_dir_error);
-    g_free(init_progfile_dir_error);
-  } else {
-    init_report_err(failure_message, NULL, NULL, NULL);
+  init_report_err(failure_message, NULL, NULL, NULL);
 
-    /* Scan for plugins.  This does *not* call their registration routines;
-       that's done later.
+  /* Scan for plugins.  This does *not* call their registration routines;
+     that's done later.
 
-       Don't report failures to load plugins because most (non-wiretap)
-       plugins *should* fail to load (because we're not linked against
-       libwireshark and dissector plugins need libwireshark). */
-    scan_plugins(DONT_REPORT_LOAD_FAILURE);
+     Don't report failures to load plugins because most (non-wiretap)
+     plugins *should* fail to load (because we're not linked against
+     libwireshark and dissector plugins need libwireshark). */
+  scan_plugins(DONT_REPORT_LOAD_FAILURE);
 
-    /* Register all libwiretap plugin modules. */
-    register_all_wiretap_modules();
-  }
+  /* Register all libwiretap plugin modules. */
+  register_all_wiretap_modules();
 #endif
 
   /* Process the options */
diff --git a/captype.c b/captype.c
index 6926df01fc..133a8bf37e 100644
--- a/captype.c
+++ b/captype.c
@@ -86,6 +86,7 @@ main(int argc, char *argv[])
 {
   GString *comp_info_str;
   GString *runtime_info_str;
+  char  *init_progfile_dir_error;
   wtap  *wth;
   int    err;
   gchar *err_info;
@@ -98,10 +99,6 @@ main(int argc, char *argv[])
       {0, 0, 0, 0 }
   };
 
-#ifdef HAVE_PLUGINS
-  char  *init_progfile_dir_error;
-#endif
-
   /* Set the C-language locale to the native environment. */
   setlocale(LC_ALL, "");
 
@@ -131,26 +128,33 @@ main(int argc, char *argv[])
    */
   init_process_policies();
 
+  /*
+   * Attempt to get the pathname of the directory containing the
+   * executable file.
+   */
+  init_progfile_dir_error = init_progfile_dir(argv[0], main);
+  if (init_progfile_dir_error != NULL) {
+    fprintf(stderr,
+            "captype: Can't get pathname of directory containing the captype program: %s.\n",
+            init_progfile_dir_error);
+    g_free(init_progfile_dir_error);
+  }
+
   wtap_init();
 
 #ifdef HAVE_PLUGINS
-  if ((init_progfile_dir_error = init_progfile_dir(argv[0], main))) {
-    g_warning("captype: init_progfile_dir(): %s", init_progfile_dir_error);
-    g_free(init_progfile_dir_error);
-  } else {
-    init_report_err(failure_message,NULL,NULL,NULL);
+  init_report_err(failure_message,NULL,NULL,NULL);
 
-    /* Scan for plugins.  This does *not* call their registration routines;
-       that's done later.
+  /* Scan for plugins.  This does *not* call their registration routines;
+     that's done later.
 
-       Don't report failures to load plugins because most (non-wiretap)
-       plugins *should* fail to load (because we're not linked against
-       libwireshark and dissector plugins need libwireshark). */
-    scan_plugins(DONT_REPORT_LOAD_FAILURE);
+     Don't report failures to load plugins because most (non-wiretap)
+     plugins *should* fail to load (because we're not linked against
+     libwireshark and dissector plugins need libwireshark). */
+  scan_plugins(DONT_REPORT_LOAD_FAILURE);
 
-    /* Register all libwiretap plugin modules. */
-    register_all_wiretap_modules();
-  }
+  /* Register all libwiretap plugin modules. */
+  register_all_wiretap_modules();
 #endif
 
   /* Process the options */
diff --git a/dftest.c b/dftest.c
index 888bfd1fad..9959c6b1d8 100644
--- a/dftest.c
+++ b/dftest.c
@@ -68,12 +68,14 @@ main(int argc, char **argv)
 	init_process_policies();
 
 	/*
-	 * Attempt to get the pathname of the executable file.
+	 * Attempt to get the pathname of the directory containing the
+	 * executable file.
 	 */
 	init_progfile_dir_error = init_progfile_dir(argv[0], main);
 	if (init_progfile_dir_error != NULL) {
-		fprintf(stderr, "dftest: Can't get pathname of dftest program: %s.\n",
+		fprintf(stderr, "dftest: Can't get pathname of directory containing the dftest program: %s.\n",
 			init_progfile_dir_error);
+		g_free(init_progfile_dir_error);
 	}
 
 	init_report_err(failure_message, open_failure_message,
diff --git a/editcap.c b/editcap.c
index 6b6e27ab0e..f2da469e41 100644
--- a/editcap.c
+++ b/editcap.c
@@ -942,6 +942,7 @@ main(int argc, char *argv[])
 {
     GString      *comp_info_str;
     GString      *runtime_info_str;
+    char         *init_progfile_dir_error;
     wtap         *wth;
     int           i, j, read_err, write_err;
     gchar        *read_err_info, *write_err_info;
@@ -982,10 +983,6 @@ main(int argc, char *argv[])
     GArray                      *nrb_hdrs = NULL;
     char                        *shb_user_appl;
 
-#ifdef HAVE_PLUGINS
-    char* init_progfile_dir_error;
-#endif
-
     cmdarg_err_init(failure_message, failure_message_cont);
 
 #ifdef _WIN32
@@ -1014,27 +1011,34 @@ main(int argc, char *argv[])
      */
     init_process_policies();
 
+    /*
+     * Attempt to get the pathname of the directory containing the
+     * executable file.
+     */
+    init_progfile_dir_error = init_progfile_dir(argv[0], main);
+    if (init_progfile_dir_error != NULL) {
+        fprintf(stderr,
+                "editcap: Can't get pathname of directory containing the editcap program: %s.\n",
+                init_progfile_dir_error);
+        g_free(init_progfile_dir_error);
+    }
+
     wtap_init();
 
 #ifdef HAVE_PLUGINS
     /* Register wiretap plugins */
-    if ((init_progfile_dir_error = init_progfile_dir(argv[0], main))) {
-        g_warning("editcap: init_progfile_dir(): %s", init_progfile_dir_error);
-        g_free(init_progfile_dir_error);
-    } else {
-        init_report_err(failure_message,NULL,NULL,NULL);
+    init_report_err(failure_message,NULL,NULL,NULL);
 
-        /* Scan for plugins.  This does *not* call their registration routines;
-           that's done later.
+    /* Scan for plugins.  This does *not* call their registration routines;
+       that's done later.
 
-           Don't report failures to load plugins because most (non-wiretap)
-           plugins *should* fail to load (because we're not linked against
-           libwireshark and dissector plugins need libwireshark). */
-        scan_plugins(DONT_REPORT_LOAD_FAILURE);
+       Don't report failures to load plugins because most (non-wiretap)
+       plugins *should* fail to load (because we're not linked against
+       libwireshark and dissector plugins need libwireshark). */
+    scan_plugins(DONT_REPORT_LOAD_FAILURE);
 
-        /* Register all libwiretap plugin modules. */
-        register_all_wiretap_modules();
-    }
+    /* Register all libwiretap plugin modules. */
+    register_all_wiretap_modules();
 #endif
 
     /* Process the options */
diff --git a/mergecap.c b/mergecap.c
index f3cf9224e8..fd2c2838c3 100644
--- a/mergecap.c
+++ b/mergecap.c
@@ -242,6 +242,7 @@ main(int argc, char *argv[])
 {
   GString            *comp_info_str;
   GString            *runtime_info_str;
+  char               *init_progfile_dir_error;
   int                 opt;
   static const struct option long_options[] = {
       {"help", no_argument, NULL, 'h'},
@@ -266,10 +267,6 @@ main(int argc, char *argv[])
   gboolean            use_stdout         = FALSE;
   merge_progress_callback_t cb;
 
-#ifdef HAVE_PLUGINS
-  char  *init_progfile_dir_error;
-#endif
-
   cmdarg_err_init(mergecap_cmdarg_err, mergecap_cmdarg_err_cont);
 
 #ifdef _WIN32
@@ -298,27 +295,33 @@ main(int argc, char *argv[])
    */
   init_process_policies();
 
+  /*
+   * Attempt to get the pathname of the directory containing the
+   * executable file.
+   */
+  init_progfile_dir_error = init_progfile_dir(argv[0], main);
+  if (init_progfile_dir_error != NULL) {
+    fprintf(stderr,
+            "mergecap: Can't get pathname of directory containing the mergecap program: %s.\n",
+            init_progfile_dir_error);
+    g_free(init_progfile_dir_error);
+  }
+
   wtap_init();
 
 #ifdef HAVE_PLUGINS
-  /* Register wiretap plugins */
-  if ((init_progfile_dir_error = init_progfile_dir(argv[0], main))) {
-    g_warning("mergecap: init_progfile_dir(): %s", init_progfile_dir_error);
-    g_free(init_progfile_dir_error);
-  } else {
-    init_report_err(failure_message,NULL,NULL,NULL);
+  init_report_err(failure_message,NULL,NULL,NULL);
 
-    /* Scan for plugins.  This does *not* call their registration routines;
-       that's done later.
+  /* Scan for plugins.  This does *not* call their registration routines;
+     that's done later.
 
-       Don't report failures to load plugins because most (non-wiretap)
-       plugins *should* fail to load (because we're not linked against
-       libwireshark and dissector plugins need libwireshark).*/
-    scan_plugins(DONT_REPORT_LOAD_FAILURE);
+     Don't report failures to load plugins because most (non-wiretap)
+     plugins *should* fail to load (because we're not linked against
+     libwireshark and dissector plugins need libwireshark).*/
+  scan_plugins(DONT_REPORT_LOAD_FAILURE);
 
-    /* Register all libwiretap plugin modules. */
-    register_all_wiretap_modules();
-  }
+  /* Register all libwiretap plugin modules. */
+  register_all_wiretap_modules();
 #endif
 
   /* Process the options first */
diff --git a/randpkt.c b/randpkt.c
index 854e5c6bc2..5035fd3fec 100644
--- a/randpkt.c
+++ b/randpkt.c
@@ -110,6 +110,7 @@ usage(gboolean is_error)
 int
 main(int argc, char **argv)
 {
+	char                   *init_progfile_dir_error;
 	int			opt;
 	int			produce_type = -1;
 	char			*produce_filename = NULL;
@@ -124,15 +125,23 @@ main(int argc, char **argv)
 		{0, 0, 0, 0 }
 	};
 
-#ifdef HAVE_PLUGINS
-	char  *init_progfile_dir_error;
-#endif
-
 	/*
 	 * Get credential information for later use.
 	 */
 	init_process_policies();
 
+	/*
+	 * Attempt to get the pathname of the directory containing the
+	 * executable file.
+	 */
+	init_progfile_dir_error = init_progfile_dir(argv[0], main);
+	if (init_progfile_dir_error != NULL) {
+		fprintf(stderr,
+		    "capinfos: Can't get pathname of directory containing the capinfos program: %s.\n",
+		    init_progfile_dir_error);
+		g_free(init_progfile_dir_error);
+	}
+
 	wtap_init();
 
 	cmdarg_err_init(failure_message, failure_message_cont);
@@ -144,24 +153,19 @@ main(int argc, char **argv)
 
 #ifdef HAVE_PLUGINS
 	/* Register wiretap plugins */
-	if ((init_progfile_dir_error = init_progfile_dir(argv[0], main))) {
-		g_warning("randpkt: init_progfile_dir(): %s", init_progfile_dir_error);
-		g_free(init_progfile_dir_error);
-	} else {
-		init_report_err(failure_message,NULL,NULL,NULL);
+	init_report_err(failure_message,NULL,NULL,NULL);
 
-		/* Scan for plugins.  This does *not* call their registration routines;
-		   that's done later.
+	/* Scan for plugins.  This does *not* call their registration routines;
+	   that's done later.
 
-		   Don't report failures to load plugins because most
-		   (non-wiretap) plugins *should* fail to load (because
-		   we're not linked against libwireshark and dissector
-		   plugins need libwireshark). */
-		scan_plugins(DONT_REPORT_LOAD_FAILURE);
+	   Don't report failures to load plugins because most
+	   (non-wiretap) plugins *should* fail to load (because
+	   we're not linked against libwireshark and dissector
+	   plugins need libwireshark). */
+	scan_plugins(DONT_REPORT_LOAD_FAILURE);
 
-		/* Register all libwiretap plugin modules. */
-		register_all_wiretap_modules();
-	}
+	/* Register all libwiretap plugin modules. */
+	register_all_wiretap_modules();
 #endif
 
 	while ((opt = getopt_long(argc, argv, "b:c:ht:r", long_options, NULL)) != -1) {
diff --git a/rawshark.c b/rawshark.c
index ed88215047..f9d0a5702c 100644
--- a/rawshark.c
+++ b/rawshark.c
@@ -485,7 +485,8 @@ main(int argc, char *argv[])
     string_fmts = g_ptr_array_new();
 
     /*
-     * Attempt to get the pathname of the executable file.
+     * Attempt to get the pathname of the directory containing the
+     * executable file.
      */
     init_progfile_dir_error = init_progfile_dir(argv[0], main);
     if (init_progfile_dir_error != NULL) {
diff --git a/reordercap.c b/reordercap.c
index 004cb158b7..4f453dc464 100644
--- a/reordercap.c
+++ b/reordercap.c
@@ -167,6 +167,7 @@ main(int argc, char *argv[])
 {
     GString *comp_info_str;
     GString *runtime_info_str;
+    char *init_progfile_dir_error;
     wtap *wth = NULL;
     wtap_dumper *pdh = NULL;
     struct wtap_pkthdr dump_phdr;
@@ -195,10 +196,6 @@ main(int argc, char *argv[])
     char *infile;
     const char *outfile;
 
-#ifdef HAVE_PLUGINS
-    char  *init_progfile_dir_error;
-#endif
-
     /* Get the compile-time version information string */
     comp_info_str = get_compiled_version_info(NULL, NULL);
 
@@ -215,32 +212,39 @@ main(int argc, char *argv[])
     g_string_free(comp_info_str, TRUE);
     g_string_free(runtime_info_str, TRUE);
 
-  /*
-   * Get credential information for later use.
-   */
-  init_process_policies();
+    /*
+     * Get credential information for later use.
+     */
+    init_process_policies();
+
+    /*
+     * Attempt to get the pathname of the directory containing the
+     * executable file.
+     */
+    init_progfile_dir_error = init_progfile_dir(argv[0], main);
+    if (init_progfile_dir_error != NULL) {
+        fprintf(stderr,
+                "reordercap: Can't get pathname of directory containing the reordercap program: %s.\n",
+                init_progfile_dir_error);
+        g_free(init_progfile_dir_error);
+    }
 
-  wtap_init();
+    wtap_init();
 
 #ifdef HAVE_PLUGINS
     /* Register wiretap plugins */
-    if ((init_progfile_dir_error = init_progfile_dir(argv[0], main))) {
-        g_warning("reordercap: init_progfile_dir(): %s", init_progfile_dir_error);
-        g_free(init_progfile_dir_error);
-    } else {
-        init_report_err(failure_message,NULL,NULL,NULL);
+    init_report_err(failure_message,NULL,NULL,NULL);
 
-        /* Scan for plugins.  This does *not* call their registration routines;
-           that's done later.
+    /* Scan for plugins.  This does *not* call their registration routines;
+       that's done later.
 
-           Don't report failures to load plugins because most (non-wiretap)
-           plugins *should* fail to load (because we're not linked against
-           libwireshark and dissector plugins need libwireshark). */
-        scan_plugins(DONT_REPORT_LOAD_FAILURE);
+       Don't report failures to load plugins because most (non-wiretap)
+       plugins *should* fail to load (because we're not linked against
+       libwireshark and dissector plugins need libwireshark). */
+    scan_plugins(DONT_REPORT_LOAD_FAILURE);
 
-        /* Register all libwiretap plugin modules. */
-        register_all_wiretap_modules();
-    }
+    /* Register all libwiretap plugin modules. */
+    register_all_wiretap_modules();
 #endif
 
     /* Process the options first */
diff --git a/tfshark.c b/tfshark.c
index a1be81b307..333777e01a 100644
--- a/tfshark.c
+++ b/tfshark.c
@@ -393,12 +393,15 @@ main(int argc, char *argv[])
   print_current_user();
 
   /*
-   * Attempt to get the pathname of the executable file.
+   * Attempt to get the pathname of the directory containing the
+   * executable file.
    */
   init_progfile_dir_error = init_progfile_dir(argv[0], main);
   if (init_progfile_dir_error != NULL) {
-    fprintf(stderr, "tfshark: Can't get pathname of tfshark program: %s.\n",
+    fprintf(stderr,
+            "tfshark: Can't get pathname of directory containing the tfshark program: %s.\n",
             init_progfile_dir_error);
+    g_free(init_progfile_dir_error);
   }
 
   initialize_funnel_ops();
diff --git a/tshark.c b/tshark.c
index 0e90434989..137a7dcead 100644
--- a/tshark.c
+++ b/tshark.c
@@ -736,12 +736,17 @@ main(int argc, char *argv[])
   print_current_user();
 
   /*
-   * Attempt to get the pathname of the executable file.
+   * Attempt to get the pathname of the directory containing the
+   * executable file.
    */
   init_progfile_dir_error = init_progfile_dir(argv[0], main);
   if (init_progfile_dir_error != NULL) {
-    fprintf(stderr, "tshark: Can't get pathname of tshark program: %s.\n",
+    fprintf(stderr,
+            "tshark: Can't get pathname of directory containing the tshark program: %s.\n"
+            "It won't be possible to capture traffic.\n"
+            "Report this to the Wireshark developers.",
             init_progfile_dir_error);
+    g_free(init_progfile_dir_error);
   }
 
   initialize_funnel_ops();
diff --git a/ui/gtk/main.c b/ui/gtk/main.c
index 4cb793f775..ce5ab50d44 100644
--- a/ui/gtk/main.c
+++ b/ui/gtk/main.c
@@ -2115,7 +2115,8 @@ main(int argc, char *argv[])
     relinquish_special_privs_perm();
 
     /*
-     * Attempt to get the pathname of the executable file.
+     * Attempt to get the pathname of the directory containing the
+     * executable file.
      */
     init_progfile_dir_error = init_progfile_dir(argv[0], main);
 
@@ -2280,7 +2281,7 @@ main(int argc, char *argv[])
     splash_win = splash_new("Loading Wireshark ...");
     if (init_progfile_dir_error != NULL) {
         simple_dialog(ESD_TYPE_WARN, ESD_BTN_OK,
-                      "Can't get pathname of Wireshark: %s.\n"
+                      "Can't get pathname of directory containing Wireshark: %s.\n"
                       "It won't be possible to capture traffic.\n"
                       "Report this to the Wireshark developers.",
                       init_progfile_dir_error);
diff --git a/wireshark-qt.cpp b/wireshark-qt.cpp
index 504ff0a6f8..f0f1b084d3 100644
--- a/wireshark-qt.cpp
+++ b/wireshark-qt.cpp
@@ -375,7 +375,8 @@ int main(int argc, char *qt_argv[])
     relinquish_special_privs_perm();
 
     /*
-     * Attempt to get the pathname of the executable file.
+     * Attempt to get the pathname of the directory containing the
+     * executable file.
      */
     /* init_progfile_dir_error = */ init_progfile_dir(argv[0],
         (int (*)(int, char **)) get_gui_compiled_info);
diff --git a/wsutil/plugins.c b/wsutil/plugins.c
index 5bb530dd23..12f85c962d 100644
--- a/wsutil/plugins.c
+++ b/wsutil/plugins.c
@@ -276,9 +276,9 @@ scan_plugins(plugin_load_failure_mode mode)
     char *plugin_dir_path;
     char *plugins_pers_dir;
     WS_DIR *dir;                /* scanned directory */
-    WS_DIRENT *file;                /* current file */
+    WS_DIRENT *file;            /* current file */
 
-    if (plugin_list == NULL)      /* ensure scan_plugins is only run once */
+    if (plugin_list == NULL)    /* only scan for plugins once */
     {
         /*
          * Scan the global plugin directory.
@@ -288,6 +288,11 @@ scan_plugins(plugin_load_failure_mode mode)
          * they will contain plugins in the case of an in-tree build.
          */
         plugin_dir = get_plugin_dir();
+        if (plugin_dir == NULL)
+        {
+            /* We couldn't find the plugin directory. */
+            return;
+        }
         if (running_in_build_directory())
         {
             if ((dir = ws_dir_open(plugin_dir, 0, NULL)) != NULL)