Pull the error-reporting code for preference files into read_prefs().

No need to duplicate it in N different programs.

Update comments while we're at it.

Change-Id: I3096cbe5448a19363eff6303bdd54e522dae9336
Reviewed-on: https://code.wireshark.org/review/20973
Reviewed-by: Guy Harris <guy@alum.mit.edu>

9 files changed, 29 insertions, 249 deletions

diff --git a/dftest.c b/dftest.c
index 7d7c868e9c..81e5185260 100644
--- a/dftest.c
+++ b/dftest.c
@@ -58,9 +58,6 @@ main(int argc, char **argv)
 {
 	char		*init_progfile_dir_error;
 	char		*text;
-	char		*gpf_path, *pf_path;
-	int		gpf_open_errno, gpf_read_errno;
-	int		pf_open_errno, pf_read_errno;
 	dfilter_t	*df;
 	gchar		*err_msg;
 
@@ -109,32 +106,7 @@ main(int argc, char **argv)
 	/* set the c-language locale to the native environment. */
 	setlocale(LC_ALL, "");
 
-	read_prefs(&gpf_open_errno, &gpf_read_errno, &gpf_path,
-		&pf_open_errno, &pf_read_errno, &pf_path);
-	if (gpf_path != NULL) {
-		if (gpf_open_errno != 0) {
-			fprintf(stderr,
-				"can't open global preferences file \"%s\": %s.\n",
-				pf_path, g_strerror(gpf_open_errno));
-		}
-		if (gpf_read_errno != 0) {
-			fprintf(stderr,
-				"I/O error reading global preferences file \"%s\": %s.\n",
-				pf_path, g_strerror(gpf_read_errno));
-		}
-	}
-	if (pf_path != NULL) {
-		if (pf_open_errno != 0) {
-			fprintf(stderr,
-				"can't open your preferences file \"%s\": %s.\n",
-				pf_path, g_strerror(pf_open_errno));
-		}
-		if (pf_read_errno != 0) {
-			fprintf(stderr,
-				"I/O error reading your preferences file \"%s\": %s.\n",
-				pf_path, g_strerror(pf_read_errno));
-		}
-	}
+	read_prefs();
 
 	/* notify all registered modules that have had any of their preferences
 	changed either from one of the preferences file or from the command
diff --git a/epan/prefs.c b/epan/prefs.c
index f2cee4aa88..293e8e1dbb 100644
--- a/epan/prefs.c
+++ b/epan/prefs.c
@@ -45,6 +45,7 @@
 #include "print.h"
 #include <wsutil/file_util.h>
 #include <wsutil/ws_printf.h> /* ws_g_warning */
+#include <wsutil/report_message.h>
 
 #include <epan/prefs-int.h>
 #include <epan/uat-int.h>
@@ -4184,19 +4185,10 @@ prefs_reset(void)
 
 /* Read the preferences file, fill in "prefs", and return a pointer to it.
 
-   If we got an error (other than "it doesn't exist") trying to read
-   the global preferences file, stuff the errno into "*gpf_errno_return"
-   and a pointer to the path of the file into "*gpf_path_return", and
-   return NULL.
-
-   If we got an error (other than "it doesn't exist") trying to read
-   the user's preferences file, stuff the errno into "*pf_errno_return"
-   and a pointer to the path of the file into "*pf_path_return", and
-   return NULL. */
+   If we got an error (other than "it doesn't exist") we report it through
+   the UI. */
 e_prefs *
-read_prefs(int *gpf_errno_return, int *gpf_read_errno_return,
-           char **gpf_path_return, int *pf_errno_return,
-           int *pf_read_errno_return, char **pf_path_return)
+read_prefs(void)
 {
     int         err;
     char        *pf_path;
@@ -4237,7 +4229,6 @@ read_prefs(int *gpf_errno_return, int *gpf_read_errno_return,
      * XXX - if it failed for a reason other than "it doesn't exist",
      * report the error.
      */
-    *gpf_path_return = NULL;
     if (pf != NULL) {
         /*
          * Start out the counters of "mgcp.{tcp,udp}.port" entries we've
@@ -4249,21 +4240,19 @@ read_prefs(int *gpf_errno_return, int *gpf_read_errno_return,
         /* We succeeded in opening it; read it. */
         err = read_prefs_file(gpf_path, pf, set_pref, NULL);
         if (err != 0) {
-            /* We had an error reading the file; return the errno and the
-               pathname, so our caller can report the error. */
-            *gpf_errno_return = 0;
-            *gpf_read_errno_return = err;
-            *gpf_path_return = gpf_path;
+            /* We had an error reading the file; report it. */
+            report_warning("Error reading global preferences file \"%s\": %s.",
+                           gpf_path, g_strerror(err));
         }
         fclose(pf);
     } else {
         /* We failed to open it.  If we failed for some reason other than
-           "it doesn't exist", return the errno and the pathname, so our
-           caller can report the error. */
+           "it doesn't exist", report the error. */
         if (errno != ENOENT) {
-            *gpf_errno_return = errno;
-            *gpf_read_errno_return = 0;
-            *gpf_path_return = gpf_path;
+            if (errno != 0) {
+                report_warning("Can't open global preferences file \"%s\": %s.",
+                               gpf_path, g_strerror(errno));
+            }
         }
     }
 
@@ -4271,7 +4260,6 @@ read_prefs(int *gpf_errno_return, int *gpf_read_errno_return,
     pf_path = get_persconffile_path(PF_NAME, TRUE);
 
     /* Read the user's preferences file, if it exists. */
-    *pf_path_return = NULL;
     if ((pf = ws_fopen(pf_path, "r")) != NULL) {
         /*
          * Start out the counters of "mgcp.{tcp,udp}.port" entries we've
@@ -4283,11 +4271,9 @@ read_prefs(int *gpf_errno_return, int *gpf_read_errno_return,
         /* We succeeded in opening it; read it. */
         err = read_prefs_file(pf_path, pf, set_pref, NULL);
         if (err != 0) {
-            /* We had an error reading the file; return the errno and the
-               pathname, so our caller can report the error. */
-            *pf_errno_return = 0;
-            *pf_read_errno_return = err;
-            *pf_path_return = pf_path;
+            /* We had an error reading the file; report it. */
+            report_warning("Error reading your preferences file \"%s\": %s.",
+                           pf_path, g_strerror(err));
         } else
             g_free(pf_path);
         fclose(pf);
@@ -4296,9 +4282,8 @@ read_prefs(int *gpf_errno_return, int *gpf_read_errno_return,
            "it doesn't exist", return the errno and the pathname, so our
            caller can report the error. */
         if (errno != ENOENT) {
-            *pf_errno_return = errno;
-            *pf_read_errno_return = 0;
-            *pf_path_return = pf_path;
+            report_warning("Can't open your preferences file \"%s\": %s.",
+                           pf_path, g_strerror(errno));
         } else
             g_free(pf_path);
     }
diff --git a/epan/prefs.h b/epan/prefs.h
index 74ea1a0217..77a3624ff5 100644
--- a/epan/prefs.h
+++ b/epan/prefs.h
@@ -589,18 +589,9 @@ char *prefs_pref_to_str(pref_t *pref, pref_source_t source);
 
 /* Read the preferences file, fill in "prefs", and return a pointer to it.
 
-   If we got an error (other than "it doesn't exist") trying to read
-   the global preferences file, stuff the errno into "*gpf_errno_return"
-   on an open error and into "*gpf_read_errno_return" on a read error,
-   stuff a pointer to the path of the file into "*gpf_path_return", and
-   return NULL.
-
-   If we got an error (other than "it doesn't exist") trying to read
-   the user's preferences file, stuff the errno into "*pf_errno_return"
-   on an open error and into "*pf_read_errno_return" on a read error,
-   stuff a pointer to the path of the file into "*pf_path_return", and
-   return NULL. */
-WS_DLL_PUBLIC e_prefs *read_prefs(int *, int *, char **, int *, int *, char **);
+   If we got an error (other than "it doesn't exist") we report it through
+   the UI. */
+WS_DLL_PUBLIC e_prefs *read_prefs(void);
 
 /* Write out "prefs" to the user's preferences file, and return 0.
 
diff --git a/rawshark.c b/rawshark.c
index 248edfd228..43d76be232 100644
--- a/rawshark.c
+++ b/rawshark.c
@@ -436,9 +436,6 @@ main(int argc, char *argv[])
     struct rlimit limit;
 #endif  /* _WIN32 */
 
-    char                *gpf_path, *pf_path;
-    int                  gpf_open_errno, gpf_read_errno;
-    int                  pf_open_errno, pf_read_errno;
     gchar               *pipe_name = NULL;
     gchar               *rfilters[64];
     e_prefs             *prefs_p;
@@ -544,30 +541,7 @@ main(int argc, char *argv[])
         goto clean_exit;
     }
 
-    prefs_p = read_prefs(&gpf_open_errno, &gpf_read_errno, &gpf_path,
-                         &pf_open_errno, &pf_read_errno, &pf_path);
-    if (gpf_path != NULL) {
-        if (gpf_open_errno != 0) {
-            cmdarg_err("Can't open global preferences file \"%s\": %s.",
-                       pf_path, g_strerror(gpf_open_errno));
-        }
-        if (gpf_read_errno != 0) {
-            cmdarg_err("I/O error reading global preferences file \"%s\": %s.",
-                       pf_path, g_strerror(gpf_read_errno));
-        }
-    }
-    if (pf_path != NULL) {
-        if (pf_open_errno != 0) {
-            cmdarg_err("Can't open your preferences file \"%s\": %s.", pf_path,
-                       g_strerror(pf_open_errno));
-        }
-        if (pf_read_errno != 0) {
-            cmdarg_err("I/O error reading your preferences file \"%s\": %s.",
-                       pf_path, g_strerror(pf_read_errno));
-        }
-        g_free(pf_path);
-        pf_path = NULL;
-    }
+    prefs_p = read_prefs();
 
     /*
      * Read the files that enable and disable protocols and heuristic
diff --git a/sharkd.c b/sharkd.c
index 64669455d8..3b10167338 100644
--- a/sharkd.c
+++ b/sharkd.c
@@ -122,11 +122,8 @@ main(int argc, char *argv[])
   GString             *runtime_info_str;
   char                *init_progfile_dir_error;
 
-  char                *gpf_path, *pf_path;
   char                *cf_path;
   char                *err_msg = NULL;
-  int                  gpf_open_errno, gpf_read_errno;
-  int                  pf_open_errno, pf_read_errno;
   int                  cf_open_errno;
   e_prefs             *prefs_p;
   int                  ret = EXIT_SUCCESS;
@@ -209,30 +206,7 @@ main(int argc, char *argv[])
   /* load the decode as entries of this profile */
   load_decode_as_entries();
 
-  prefs_p = read_prefs(&gpf_open_errno, &gpf_read_errno, &gpf_path,
-                     &pf_open_errno, &pf_read_errno, &pf_path);
-  if (gpf_path != NULL) {
-    if (gpf_open_errno != 0) {
-      cmdarg_err("Can't open global preferences file \"%s\": %s.",
-              pf_path, g_strerror(gpf_open_errno));
-    }
-    if (gpf_read_errno != 0) {
-      cmdarg_err("I/O error reading global preferences file \"%s\": %s.",
-              pf_path, g_strerror(gpf_read_errno));
-    }
-  }
-  if (pf_path != NULL) {
-    if (pf_open_errno != 0) {
-      cmdarg_err("Can't open your preferences file \"%s\": %s.", pf_path,
-              g_strerror(pf_open_errno));
-    }
-    if (pf_read_errno != 0) {
-      cmdarg_err("I/O error reading your preferences file \"%s\": %s.",
-              pf_path, g_strerror(pf_read_errno));
-    }
-    g_free(pf_path);
-    pf_path = NULL;
-  }
+  prefs_p = read_prefs();
 
   read_filter_list(CFILTER_LIST, &cf_path, &cf_open_errno);
   if (cf_path != NULL) {
diff --git a/tfshark.c b/tfshark.c
index 0993b6181e..e72645aedb 100644
--- a/tfshark.c
+++ b/tfshark.c
@@ -334,9 +334,6 @@ main(int argc, char *argv[])
   };
   gboolean             arg_error = FALSE;
 
-  char                *gpf_path, *pf_path;
-  int                  gpf_open_errno, gpf_read_errno;
-  int                  pf_open_errno, pf_read_errno;
   int                  err;
   volatile int         exit_status = 0;
   gboolean             quiet = FALSE;
@@ -560,8 +557,7 @@ main(int argc, char *argv[])
       if (strcmp(argv[2], "column-formats") == 0)
         column_dump_column_formats();
       else if (strcmp(argv[2], "currentprefs") == 0) {
-        read_prefs(&gpf_open_errno, &gpf_read_errno, &gpf_path,
-            &pf_open_errno, &pf_read_errno, &pf_path);
+        read_prefs();
         write_prefs(NULL);
       }
       else if (strcmp(argv[2], "decodes") == 0)
@@ -601,30 +597,7 @@ main(int argc, char *argv[])
     goto clean_exit;
   }
 
-  prefs_p = read_prefs(&gpf_open_errno, &gpf_read_errno, &gpf_path,
-                     &pf_open_errno, &pf_read_errno, &pf_path);
-  if (gpf_path != NULL) {
-    if (gpf_open_errno != 0) {
-      cmdarg_err("Can't open global preferences file \"%s\": %s.",
-              pf_path, g_strerror(gpf_open_errno));
-    }
-    if (gpf_read_errno != 0) {
-      cmdarg_err("I/O error reading global preferences file \"%s\": %s.",
-              pf_path, g_strerror(gpf_read_errno));
-    }
-  }
-  if (pf_path != NULL) {
-    if (pf_open_errno != 0) {
-      cmdarg_err("Can't open your preferences file \"%s\": %s.", pf_path,
-              g_strerror(pf_open_errno));
-    }
-    if (pf_read_errno != 0) {
-      cmdarg_err("I/O error reading your preferences file \"%s\": %s.",
-              pf_path, g_strerror(pf_read_errno));
-    }
-    g_free(pf_path);
-    pf_path = NULL;
-  }
+  prefs_p = read_prefs();
 
   /*
    * Read the files that enable and disable protocols and heuristic
diff --git a/tshark.c b/tshark.c
index 348b68f0ad..b3149cb6a3 100644
--- a/tshark.c
+++ b/tshark.c
@@ -665,10 +665,7 @@ main(int argc, char *argv[])
   WSADATA              wsaData;
 #endif  /* _WIN32 */
 
-  char                *gpf_path, *pf_path;
   char                *cf_path;
-  int                  gpf_open_errno, gpf_read_errno;
-  int                  pf_open_errno, pf_read_errno;
   int                  cf_open_errno;
   int                  err;
   volatile int         exit_status = EXIT_SUCCESS;
@@ -958,8 +955,7 @@ main(int argc, char *argv[])
       if (strcmp(argv[2], "column-formats") == 0)
         column_dump_column_formats();
       else if (strcmp(argv[2], "currentprefs") == 0) {
-        read_prefs(&gpf_open_errno, &gpf_read_errno, &gpf_path,
-            &pf_open_errno, &pf_read_errno, &pf_path);
+        read_prefs();
         write_prefs(NULL);
       }
       else if (strcmp(argv[2], "decodes") == 0)
@@ -1011,30 +1007,7 @@ main(int argc, char *argv[])
 
   tshark_debug("tshark reading preferences");
 
-  prefs_p = read_prefs(&gpf_open_errno, &gpf_read_errno, &gpf_path,
-                     &pf_open_errno, &pf_read_errno, &pf_path);
-  if (gpf_path != NULL) {
-    if (gpf_open_errno != 0) {
-      cmdarg_err("Can't open global preferences file \"%s\": %s.",
-              pf_path, g_strerror(gpf_open_errno));
-    }
-    if (gpf_read_errno != 0) {
-      cmdarg_err("I/O error reading global preferences file \"%s\": %s.",
-              pf_path, g_strerror(gpf_read_errno));
-    }
-  }
-  if (pf_path != NULL) {
-    if (pf_open_errno != 0) {
-      cmdarg_err("Can't open your preferences file \"%s\": %s.", pf_path,
-              g_strerror(pf_open_errno));
-    }
-    if (pf_read_errno != 0) {
-      cmdarg_err("I/O error reading your preferences file \"%s\": %s.",
-              pf_path, g_strerror(pf_read_errno));
-    }
-    g_free(pf_path);
-    pf_path = NULL;
-  }
+  prefs_p = read_prefs();
 
   read_filter_list(CFILTER_LIST, &cf_path, &cf_open_errno);
   if (cf_path != NULL) {
diff --git a/ui/gtk/main.c b/ui/gtk/main.c
index bfc3aac287..197610f769 100644
--- a/ui/gtk/main.c
+++ b/ui/gtk/main.c
@@ -1905,46 +1905,15 @@ get_wireshark_runtime_info(GString *str)
 static e_prefs *
 read_configuration_files(void)
 {
-    int                  gpf_open_errno, gpf_read_errno;
     int                  cf_open_errno, df_open_errno;
-    char                *gpf_path, *pf_path;
     char                *cf_path, *df_path;
-    int                  pf_open_errno, pf_read_errno;
     e_prefs             *prefs_p;
 
     /* load the decode as entries of this profile */
     load_decode_as_entries();
 
     /* Read the preference files. */
-    prefs_p = read_prefs(&gpf_open_errno, &gpf_read_errno, &gpf_path,
-                         &pf_open_errno, &pf_read_errno, &pf_path);
-
-    if (gpf_path != NULL) {
-        if (gpf_open_errno != 0) {
-            simple_dialog(ESD_TYPE_WARN, ESD_BTN_OK,
-                          "Could not open global preferences file\n\"%s\": %s.",
-                          gpf_path, g_strerror(gpf_open_errno));
-        }
-        if (gpf_read_errno != 0) {
-            simple_dialog(ESD_TYPE_WARN, ESD_BTN_OK,
-                          "I/O error reading global preferences file\n\"%s\": %s.",
-                          gpf_path, g_strerror(gpf_read_errno));
-        }
-    }
-    if (pf_path != NULL) {
-        if (pf_open_errno != 0) {
-            simple_dialog(ESD_TYPE_WARN, ESD_BTN_OK,
-                          "Could not open your preferences file\n\"%s\": %s.",
-                          pf_path, g_strerror(pf_open_errno));
-        }
-        if (pf_read_errno != 0) {
-            simple_dialog(ESD_TYPE_WARN, ESD_BTN_OK,
-                          "I/O error reading your preferences file\n\"%s\": %s.",
-                          pf_path, g_strerror(pf_read_errno));
-        }
-        g_free(pf_path);
-        pf_path = NULL;
-    }
+    prefs_p = read_prefs();
 
 #ifdef _WIN32
     /* if the user wants a console to be always there, well, we should open one for him */
diff --git a/ui/qt/wireshark_application.cpp b/ui/qt/wireshark_application.cpp
index f1ef200574..a9428d534f 100644
--- a/ui/qt/wireshark_application.cpp
+++ b/ui/qt/wireshark_application.cpp
@@ -1095,11 +1095,8 @@ void WiresharkApplication::allSystemsGo()
 
 _e_prefs *WiresharkApplication::readConfigurationFiles(bool reset)
 {
-    int                  gpf_open_errno, gpf_read_errno;
     int                  cf_open_errno, df_open_errno;
-    char                *gpf_path, *pf_path;
     char                *cf_path, *df_path;
-    int                  pf_open_errno, pf_read_errno;
     e_prefs             *prefs_p;
 
     if (reset) {
@@ -1116,35 +1113,7 @@ _e_prefs *WiresharkApplication::readConfigurationFiles(bool reset)
     load_decode_as_entries();
 
     /* Read the preference files. */
-    prefs_p = read_prefs(&gpf_open_errno, &gpf_read_errno, &gpf_path,
-                         &pf_open_errno, &pf_read_errno, &pf_path);
-
-    if (gpf_path != NULL) {
-        if (gpf_open_errno != 0) {
-            simple_dialog(ESD_TYPE_WARN, ESD_BTN_OK,
-                          "Could not open global preferences file\n\"%s\": %s.", gpf_path,
-                          g_strerror(gpf_open_errno));
-        }
-        if (gpf_read_errno != 0) {
-            simple_dialog(ESD_TYPE_WARN, ESD_BTN_OK,
-                          "I/O error reading global preferences file\n\"%s\": %s.", gpf_path,
-                          g_strerror(gpf_read_errno));
-        }
-    }
-    if (pf_path != NULL) {
-        if (pf_open_errno != 0) {
-            simple_dialog(ESD_TYPE_WARN, ESD_BTN_OK,
-                          "Could not open your preferences file\n\"%s\": %s.", pf_path,
-                          g_strerror(pf_open_errno));
-        }
-        if (pf_read_errno != 0) {
-            simple_dialog(ESD_TYPE_WARN, ESD_BTN_OK,
-                          "I/O error reading your preferences file\n\"%s\": %s.", pf_path,
-                          g_strerror(pf_read_errno));
-        }
-        g_free(pf_path);
-        pf_path = NULL;
-    }
+    prefs_p = read_prefs();
 
 #ifdef _WIN32
     /* if the user wants a console to be always there, well, we should open one for him */