Clean up handling of --capture-comment.

Don't store the comments in a capture_options structure, because that's
available only if we're being built with capture support, and
--capture-comment can be used in TShark when reading a capture file and
writing another capture file, with no live capture taking place.

This means we don't handle that option in capture_opts_add_opt(); handle
it in the programs that support it.

Support writing multiple comments in dumpcap when capturing.

These changes also fix builds without pcap, and makes --capture-comment
work in Wireshark when a capture is started from the command line with
-k.

Update the help messages to indicate that --capture-comment adds a
capture comment, it doesn't change any comment (much less "the" comment,
as there isn't necessarily a single comment).

Update the man pages:

- not to presume that only pcapng files support file comments (even if
that's true now, it might not be true in the future);
- to note that multiple instances of --capture-comment are supported,
and that multiple comments will be written, whether capturing or reading
one file and writing another;
- clarify that Wireshark doesn't *discard* SHB comments other than the
first one, even though it only displays the first one;

19 files changed, 142 insertions, 86 deletions

diff --git a/capture/capture_sync.c b/capture/capture_sync.c
index ad7fbca89f..4352521fe3 100644
--- a/capture/capture_sync.c
+++ b/capture/capture_sync.c
@@ -204,7 +204,9 @@ init_pipe_args(int *argc) {
 #define ARGV_NUMBER_LEN 24
 /* a new capture run: start a new dumpcap task and hand over parameters through command line */
 gboolean
-sync_pipe_start(capture_options *capture_opts, capture_session *cap_session, info_data_t* cap_data, void (*update_cb)(void))
+sync_pipe_start(capture_options *capture_opts, GPtrArray *capture_comments,
+                capture_session *cap_session, info_data_t* cap_data,
+                void (*update_cb)(void))
 {
 #ifdef _WIN32
     HANDLE sync_pipe_read;                  /* pipe used to send messages from child to parent */
@@ -257,10 +259,10 @@ sync_pipe_start(capture_options *capture_opts, capture_session *cap_session, inf
     else
         argv = sync_pipe_add_arg(argv, &argc, "-P");
 
-    if (capture_opts->capture_comment) {
-        for (j = 0; j < capture_opts->capture_comment->len; j++) {
+    if (capture_comments != NULL) {
+        for (j = 0; j < capture_comments->len; j++) {
             argv = sync_pipe_add_arg(argv, &argc, "--capture-comment");
-            argv = sync_pipe_add_arg(argv, &argc, (char*)g_ptr_array_index(capture_opts->capture_comment, j));
+            argv = sync_pipe_add_arg(argv, &argc, (char*)g_ptr_array_index(capture_comments, j));
         }
     }
 
diff --git a/capture/capture_sync.h b/capture/capture_sync.h
index b2c6751eff..2d7b8e116b 100644
--- a/capture/capture_sync.h
+++ b/capture/capture_sync.h
@@ -35,13 +35,17 @@ struct _info_data;
  *  Most of the parameters are passed through the global capture_opts.
  *
  *  @param capture_opts the options
+ *  @param capture_comments if not NULL, a GPtrArray * to a set of comments
+ *   to put in the capture file's Section Header Block if it's a pcapng file
  *  @param cap_session a handle for the capture session
  *  @param cap_data a struct with capture info data
  *  @param update_cb update screen
  *  @return             TRUE if a capture could be started, FALSE if not
  */
 extern gboolean
-sync_pipe_start(capture_options *capture_opts, capture_session *cap_session, struct _info_data* cap_data, void(*update_cb)(void));
+sync_pipe_start(capture_options *capture_opts, GPtrArray *capture_comments,
+                capture_session *cap_session, struct _info_data* cap_data,
+                void(*update_cb)(void));
 
 /** User wants to stop capturing, gracefully close the capture child */
 extern void
diff --git a/capture_opts.c b/capture_opts.c
index e87bc9f653..504560caee 100644
--- a/capture_opts.c
+++ b/capture_opts.c
@@ -115,7 +115,6 @@ capture_opts_init(capture_options *capture_opts)
     capture_opts->autostop_filesize               = 1000;             /* 1 MB */
     capture_opts->has_autostop_duration           = FALSE;
     capture_opts->autostop_duration               = 60.0;             /* 1 min */
-    capture_opts->capture_comment                 = NULL;
 
     capture_opts->output_to_pipe                  = FALSE;
     capture_opts->capture_child                   = FALSE;
@@ -147,10 +146,6 @@ capture_opts_cleanup(capture_options *capture_opts)
         capture_opts->all_ifaces = NULL;
     }
     g_free(capture_opts->save_file);
-    if (capture_opts->capture_comment != NULL) {
-        g_ptr_array_free(capture_opts->capture_comment, TRUE);
-        capture_opts->capture_comment = NULL;
-    }
 }
 
 /* log content of capture_opts */
@@ -803,12 +798,6 @@ capture_opts_add_opt(capture_options *capture_opts, int opt, const char *optarg_
     int status, snaplen;
 
     switch(opt) {
-    case LONGOPT_CAPTURE_COMMENT:  /* capture comment */
-        if (!capture_opts->capture_comment) {
-            capture_opts->capture_comment = g_ptr_array_new_with_free_func(g_free);
-        }
-        g_ptr_array_add(capture_opts->capture_comment, g_strdup(optarg_str_p));
-        break;
     case 'a':        /* autostop criteria */
         if (set_autostop_criterion(capture_opts, optarg_str_p) == FALSE) {
             cmdarg_err("Invalid or unknown -a flag \"%s\"", optarg_str_p);
diff --git a/capture_opts.h b/capture_opts.h
index 1452f30484..660a9746bd 100644
--- a/capture_opts.h
+++ b/capture_opts.h
@@ -44,10 +44,9 @@ extern "C" {
  * In short: we must not use 1 here, which is another reason to use
  * values outside the range of ASCII graphic characters.
  */
-#define LONGOPT_CAPTURE_COMMENT   LONGOPT_BASE_CAPTURE+1
-#define LONGOPT_LIST_TSTAMP_TYPES LONGOPT_BASE_CAPTURE+2
-#define LONGOPT_SET_TSTAMP_TYPE   LONGOPT_BASE_CAPTURE+3
-#define LONGOPT_COMPRESS_TYPE     LONGOPT_BASE_CAPTURE+4
+#define LONGOPT_LIST_TSTAMP_TYPES LONGOPT_BASE_CAPTURE+1
+#define LONGOPT_SET_TSTAMP_TYPE   LONGOPT_BASE_CAPTURE+2
+#define LONGOPT_COMPRESS_TYPE     LONGOPT_BASE_CAPTURE+3
 
 /*
  * Options for capturing common to all capturing programs.
@@ -76,7 +75,6 @@ extern "C" {
 #endif
 
 #define LONGOPT_CAPTURE_COMMON \
-    {"capture-comment",       required_argument, NULL, LONGOPT_CAPTURE_COMMENT}, \
     {"autostop",              required_argument, NULL, 'a'}, \
     {"ring-buffer",           required_argument, NULL, 'b'}, \
     LONGOPT_BUFFER_SIZE \
@@ -313,8 +311,6 @@ typedef struct capture_options_tag {
                                                    is specified */
     gdouble            autostop_duration;     /**< Maximum capture duration */
 
-    GPtrArray         *capture_comment;       /** capture comment to write to the
-                                                  output file */
     gboolean           print_file_names;      /**< TRUE if printing names of completed
                                                    files as we close them */
     gchar             *print_name_to;         /**< output file name */
diff --git a/doc/dumpcap.pod b/doc/dumpcap.pod
index 19d16c5dfd..c5f043f44c 100644
--- a/doc/dumpcap.pod
+++ b/doc/dumpcap.pod
@@ -419,11 +419,14 @@ the default capture link type is used if provided.
 
 =item --capture-comment  E<lt>commentE<gt>
 
-Add a capture comment to the output file.
+Add a capture comment to the output file, if supported by the output
+file format.
 
 This option is only available if we output the captured packets to a
-single file in pcapng format. Only one capture comment may be set per
-output file.
+single file.
+
+This option may be specified multiple times.  Note that Wireshark
+currently only displays the first comment of a capture file.
 
 =item --list-time-stamp-types
 
diff --git a/doc/editcap.pod b/doc/editcap.pod
index 1d7f520e1e..cf8bcb5f16 100644
--- a/doc/editcap.pod
+++ b/doc/editcap.pod
@@ -375,12 +375,12 @@ the same command line.
 
 =item --capture-comment E<lt>commentE<gt>
 
-Adds the given comment to the Section Header Block (SHB) of the pcapng
-output file. New comments will be added I<after> any comments present in the
-input file unless B<--discard-capture-comment> is also specified.
+Adds the given comment to the output file, if supported by the output
+file format.  New comments will be added I<after> any comments present
+in the input file unless B<--discard-capture-comment> is also specified.
 
-This option may be specified multiple times. Note that Wireshark currently only
-recognizes the first comment of a capture file.
+This option may be specified multiple times.  Note that Wireshark
+currently only displays the first comment of a capture file.
 
 =item --discard-capture-comment
 
diff --git a/doc/tshark.pod b/doc/tshark.pod
index 5548b1a971..e0059d43cf 100644
--- a/doc/tshark.pod
+++ b/doc/tshark.pod
@@ -1728,13 +1728,11 @@ SMB packets exchanged by the host at IP address 1.2.3.4 .
 
 =item --capture-comment E<lt>commentE<gt>
 
-Add a capture comment to the output file.
+Add a capture comment to the output file, if supported by the output
+file format.
 
-This option is only available if a new output file in pcapng format is
-created.
-
-This option may be specified multiple times. Note that Wireshark currently only
-recognizes the first comment of a capture file.
+This option may be specified multiple times.  Note that Wireshark
+currently only displays the first comment of a capture file.
 
 =item --list-time-stamp-types
 
diff --git a/doc/wireshark.pod b/doc/wireshark.pod
index c94814901a..f9b91b19b3 100644
--- a/doc/wireshark.pod
+++ b/doc/wireshark.pod
@@ -319,7 +319,12 @@ Start with the given configuration profile.
 
 =item --capture-comment E<lt>commentE<gt>
 
-Set the capture file comment, if supported by the capture format.
+When performing a capture file from the command line, with the B<-k>
+flag, add a capture comment to the output file, if supported by the
+capture format.
+
+This option may be specified multiple times.  Note that Wireshark
+currently only displays the first comment of a capture file.
 
 =item -d  E<lt>layer typeE<gt>==E<lt>selectorE<gt>,E<lt>decode-as protocolE<gt>
 
diff --git a/dumpcap.c b/dumpcap.c
index e54725520a..e8e8323429 100644
--- a/dumpcap.c
+++ b/dumpcap.c
@@ -336,6 +336,7 @@ dumpcap_log_writer(const char *domain, enum ws_log_level level,
 
 /* capture related options */
 static capture_options global_capture_opts;
+static GPtrArray *capture_comments = NULL;
 static gboolean quiet = FALSE;
 static gboolean use_threads = FALSE;
 static guint64 start_time;
@@ -3099,7 +3100,7 @@ capture_loop_init_pcapng_output(capture_options *capture_opts, loop_data *ld,
         get_cpu_info(cpu_info_str);
 
         successful = pcapng_write_section_header_block(ld->pdh,
-                                                       (const char *)capture_opts->capture_comment,   /* Comment */
+                                                       capture_comments,   /* Comments */
                                                        cpu_info_str->str,           /* HW */
                                                        os_info_str->str,            /* OS */
                                                        get_appname_and_version(),
@@ -4815,6 +4816,7 @@ get_dumpcap_runtime_info(GString *str)
 
 #define LONGOPT_IFNAME             LONGOPT_BASE_APPLICATION+1
 #define LONGOPT_IFDESCR            LONGOPT_BASE_APPLICATION+2
+#define LONGOPT_CAPTURE_COMMENT    LONGOPT_BASE_APPLICATION+3
 
 /* And now our feature presentation... [ fade to music ] */
 int
@@ -4828,6 +4830,7 @@ main(int argc, char *argv[])
         LONGOPT_CAPTURE_COMMON
         {"ifname", required_argument, NULL, LONGOPT_IFNAME},
         {"ifdescr", required_argument, NULL, LONGOPT_IFDESCR},
+        {"capture-comment", required_argument, NULL, LONGOPT_CAPTURE_COMMENT},
         {0, 0, 0, 0 }
     };
 
@@ -5139,7 +5142,6 @@ main(int argc, char *argv[])
         case 's':        /* Set the snapshot (capture) length */
         case 'w':        /* Write to capture file x */
         case 'y':        /* Set the pcap data link type */
-        case LONGOPT_CAPTURE_COMMENT: /* add a capture comment */
 #ifdef HAVE_PCAP_REMOTE
         case 'u':        /* Use UDP for data transfer */
         case 'r':        /* Capture own RPCAP traffic too */
@@ -5183,6 +5185,12 @@ main(int argc, char *argv[])
                 exit_main(1);
             }
             break;
+        case LONGOPT_CAPTURE_COMMENT:  /* capture comment */
+            if (capture_comments == NULL) {
+                capture_comments = g_ptr_array_new_with_free_func(g_free);
+            }
+            g_ptr_array_add(capture_comments, g_strdup(optarg));
+            break;
         case 'Z':
             capture_child = TRUE;
 #ifdef _WIN32
@@ -5319,10 +5327,10 @@ main(int argc, char *argv[])
             global_capture_opts.use_pcapng = TRUE;
         }
 
-        if (global_capture_opts.capture_comment &&
+        if (capture_comments &&
             (!global_capture_opts.use_pcapng || global_capture_opts.multi_files_on)) {
-            /* XXX - for ringbuffer, should we apply the comment to each file? */
-            cmdarg_err("A capture comment can only be set if we capture into a single pcapng file.");
+            /* XXX - for ringbuffer, should we apply the comments to each file? */
+            cmdarg_err("Capture comments can only be set if we capture into a single pcapng file.");
             exit_main(1);
         }
 
diff --git a/text2pcap.c b/text2pcap.c
index a706027a86..2b2471f079 100644
--- a/text2pcap.c
+++ b/text2pcap.c
@@ -883,17 +883,20 @@ write_file_header (void)
 
     if (use_pcapng) {
         char *comment;
+        GPtrArray *comments;
 
         comment = g_strdup_printf("Generated from input file %s.", input_filename);
+        comments = g_ptr_array_new_with_free_func(g_free);
+        g_ptr_array_add(comments, comment);
         success = pcapng_write_section_header_block(output_file,
-                                                    comment,
+                                                    comments,
                                                     NULL,    /* HW */
                                                     NULL,    /* OS */
                                                     get_appname_and_version(),
                                                     -1,      /* section_length */
                                                     &bytes_written,
                                                     &err);
-        g_free(comment);
+        g_ptr_array_free(comments, TRUE);
         if (success) {
             success = pcapng_write_interface_description_block(output_file,
                                                                NULL,
diff --git a/tshark.c b/tshark.c
index 7da895d502..7b8071d54c 100644
--- a/tshark.c
+++ b/tshark.c
@@ -144,6 +144,7 @@
 #define LONGOPT_NO_DUPLICATE_KEYS       LONGOPT_BASE_APPLICATION+3
 #define LONGOPT_ELASTIC_MAPPING_FILTER  LONGOPT_BASE_APPLICATION+4
 #define LONGOPT_EXPORT_TLS_SESSION_KEYS LONGOPT_BASE_APPLICATION+5
+#define LONGOPT_CAPTURE_COMMENT         LONGOPT_BASE_APPLICATION+6
 
 capture_file cfile;
 
@@ -199,6 +200,9 @@ static json_dumper jdumper;
 /* The line separator used between packets, changeable via the -S option */
 static const char *separator = "";
 
+/* Per-file comments to be added to the output file. */
+static GPtrArray *capture_comments = NULL;
+
 static gboolean prefs_loaded = FALSE;
 
 #ifdef HAVE_LIBPCAP
@@ -248,7 +252,7 @@ typedef enum {
   PROCESS_FILE_ERROR,
   PROCESS_FILE_INTERRUPTED
 } process_file_status_t;
-static process_file_status_t process_cap_file(capture_file *, char *, int, gboolean, capture_options);
+static process_file_status_t process_cap_file(capture_file *, char *, int, gboolean, int, gint64);
 
 static gboolean process_packet_single_pass(capture_file *cf,
     epan_dissect_t *edt, gint64 offset, wtap_rec *rec, Buffer *buf,
@@ -425,7 +429,7 @@ print_usage(FILE *output)
   fprintf(output, "  -w <outfile|->           write packets to a pcapng-format file named \"outfile\"\n");
   fprintf(output, "                           (or '-' for stdout)\n");
   fprintf(output, "  --capture-comment <comment>\n");
-  fprintf(output, "                           set the capture file comment, if supported\n");
+  fprintf(output, "                           add a capture file comment, if supported\n");
   fprintf(output, "  -C <config profile>      start with specified configuration profile\n");
   fprintf(output, "  -F <output file type>    set the output file type, default is pcapng\n");
   fprintf(output, "                           an empty \"-F\" option will list the file types\n");
@@ -706,6 +710,7 @@ main(int argc, char *argv[])
     {"color", no_argument, NULL, LONGOPT_COLOR},
     {"no-duplicate-keys", no_argument, NULL, LONGOPT_NO_DUPLICATE_KEYS},
     {"elastic-mapping-filter", required_argument, NULL, LONGOPT_ELASTIC_MAPPING_FILTER},
+    {"capture-comment", required_argument, NULL, LONGOPT_CAPTURE_COMMENT},
     {0, 0, 0, 0 }
   };
   gboolean             arg_error = FALSE;
@@ -1100,7 +1105,6 @@ main(int argc, char *argv[])
 #endif
     case 's':        /* Set the snapshot (capture) length */
     case 'y':        /* Set the pcap data link type */
-    case LONGOPT_CAPTURE_COMMENT: /* add a capture comment */
 #ifdef CAN_SET_CAPTURE_BUFFER_SIZE
     case 'B':        /* Buffer size */
 #endif
@@ -1476,6 +1480,12 @@ main(int argc, char *argv[])
       no_duplicate_keys = TRUE;
       node_children_grouper = proto_node_group_children_by_json_key;
       break;
+    case LONGOPT_CAPTURE_COMMENT:  /* capture comment */
+      if (capture_comments == NULL) {
+        capture_comments = g_ptr_array_new_with_free_func(g_free);
+      }
+      g_ptr_array_add(capture_comments, g_strdup(optarg));
+      break;
     default:
     case '?':        /* Bad flag - print usage message */
       switch(optopt) {
@@ -1710,7 +1720,7 @@ main(int argc, char *argv[])
         exit_status = INVALID_OPTION;
         goto clean_exit;
       }
-      if (global_capture_opts.capture_comment) {
+      if (capture_comments != NULL) {
         if (global_capture_opts.saving_to_file) {
           /* They specified a "-w" flag, so we'll be saving to a capture file.
            * This is fine if they're using pcapng.
@@ -1767,8 +1777,8 @@ main(int argc, char *argv[])
           exit_status = INVALID_OPTION;
           goto clean_exit;
         }
-        if (global_capture_opts.capture_comment && !use_pcapng) {
-          cmdarg_err("A capture comment can only be written to a pcapng file.");
+        if (capture_comments != NULL && !use_pcapng) {
+          cmdarg_err("Capture comments can only be written to a pcapng file.");
           exit_status = INVALID_OPTION;
           goto clean_exit;
         }
@@ -1828,8 +1838,8 @@ main(int argc, char *argv[])
           exit_status = INVALID_OPTION;
           goto clean_exit;
         }
-        if (global_capture_opts.capture_comment) {
-          cmdarg_err("A capture comment was specified, but "
+        if (capture_comments != NULL) {
+          cmdarg_err("Capture comments were specified, but "
             "the capture isn't being saved to a file.");
           exit_status = INVALID_OPTION;
           goto clean_exit;
@@ -2090,13 +2100,14 @@ main(int argc, char *argv[])
     /* Process the packets in the file */
     ws_debug("tshark: invoking process_cap_file() to process the packets");
     TRY {
-#ifndef HAVE_LIBPCAP
-      global_capture_opts.has_autostop_packets = max_packet_count > 0;
-      global_capture_opts.autostop_packets = max_packet_count;
-      global_capture_opts.has_autostop_filesize = FALSE;
-      global_capture_opts.autostop_filesize = 0;
+      status = process_cap_file(&cfile, output_file_name, out_file_type, out_file_name_res,
+#ifdef HAVE_LIBPCAP
+          global_capture_opts.has_autostop_packets ? global_capture_opts.autostop_packets : 0,
+          global_capture_opts.has_autostop_filesize ? global_capture_opts.autostop_filesize : 0);
+#else
+          max_packet_count,
+          0);
 #endif
-      status = process_cap_file(&cfile, output_file_name, out_file_type, out_file_name_res, global_capture_opts);
     }
     CATCH(OutOfMemoryError) {
       fprintf(stderr,
@@ -2541,7 +2552,8 @@ capture(void)
   fflush(stderr);
   g_string_free(str, TRUE);
 
-  ret = sync_pipe_start(&global_capture_opts, &global_capture_session, &global_info_data, NULL);
+  ret = sync_pipe_start(&global_capture_opts, capture_comments,
+                        &global_capture_session, &global_info_data, NULL);
 
   if (!ret)
     return FALSE;
@@ -3535,7 +3547,7 @@ process_cap_file_single_pass(capture_file *cf, wtap_dumper *pdh,
 
 static process_file_status_t
 process_cap_file(capture_file *cf, char *save_file, int out_file_type,
-    gboolean out_file_name_res, capture_options capture_opts)
+    gboolean out_file_name_res, int max_packet_count, gint64 max_byte_count)
 {
   process_file_status_t status = PROCESS_FILE_SUCCEEDED;
   wtap_dumper *pdh;
@@ -3548,13 +3560,6 @@ process_cap_file(capture_file *cf, char *save_file, int out_file_type,
   wtap_dump_params params = WTAP_DUMP_PARAMS_INIT;
   char        *shb_user_appl;
   pass_status_t first_pass_status, second_pass_status;
-  int          max_packet_count = 0;
-  int          max_byte_count = 0;
-
-  if (capture_opts.has_autostop_packets)
-    max_packet_count = capture_opts.autostop_packets;
-  if (capture_opts.has_autostop_filesize)
-    max_byte_count = capture_opts.autostop_filesize;
 
   if (save_file != NULL) {
     /* Set up to write to the capture file. */
@@ -3565,10 +3570,11 @@ process_cap_file(capture_file *cf, char *save_file, int out_file_type,
       /* this is free'd by wtap_block_unref() later */
       wtap_block_add_string_option_format(g_array_index(params.shb_hdrs, wtap_block_t, 0), OPT_SHB_USERAPPL, "%s", get_appname_and_version());
     }
-    if (capture_opts.capture_comment != NULL) {
-      guint i;
-      for (i = 0; i < capture_opts.capture_comment->len; i++) {
-        wtap_block_add_string_option_format(g_array_index(params.shb_hdrs, wtap_block_t, 0), OPT_COMMENT, "%s", (char*)g_ptr_array_index(capture_opts.capture_comment, i));
+    if (capture_comments != NULL) {
+      for (guint i = 0; i < capture_comments->len; i++) {
+        wtap_block_add_string_option_format(g_array_index(params.shb_hdrs, wtap_block_t, 0),
+                                            OPT_COMMENT, "%s",
+                                            (char *)g_ptr_array_index(capture_comments, i));
       }
     }
 
diff --git a/ui/capture.c b/ui/capture.c
index b88c86efdd..cff9d4ae6f 100644
--- a/ui/capture.c
+++ b/ui/capture.c
@@ -117,7 +117,9 @@ capture_callback_remove(capture_callback_t func, gpointer user_data)
  * @return TRUE if the capture starts successfully, FALSE otherwise.
  */
 gboolean
-capture_start(capture_options *capture_opts, capture_session *cap_session, info_data_t* cap_data, void(*update_cb)(void))
+capture_start(capture_options *capture_opts, GPtrArray *capture_comments,
+              capture_session *cap_session, info_data_t* cap_data,
+              void(*update_cb)(void))
 {
     GString *source;
 
@@ -128,7 +130,8 @@ capture_start(capture_options *capture_opts, capture_session *cap_session, info_
     cf_set_tempfile_source((capture_file *)cap_session->cf, source->str);
     g_string_free(source, TRUE);
     /* try to start the capture child process */
-    if (!sync_pipe_start(capture_opts, cap_session, cap_data, update_cb)) {
+    if (!sync_pipe_start(capture_opts, capture_comments, cap_session,
+                         cap_data, update_cb)) {
         /* We failed to start the capture child. */
         if(capture_opts->save_file != NULL) {
             g_free(capture_opts->save_file);
diff --git a/ui/capture.h b/ui/capture.h
index 6589dfc8e7..f02e18ed92 100644
--- a/ui/capture.h
+++ b/ui/capture.h
@@ -60,13 +60,17 @@ capture_input_init(capture_session *cap_session, capture_file *cf);
  * Start a capture session.
  *
  * @param capture_opts the numerous capture options
+ * @param capture_comments if not NULL, a GPtrArray * to a set of comments
+ *  to put in the capture file's Section Header Block if it's a pcapng file
  * @param cap_session the handle for the capture session
  * @param cap_data a struct with capture info data
  * @param update_cb update screen
  * @return TRUE if the capture starts successfully, FALSE otherwise.
  */
 extern gboolean
-capture_start(capture_options *capture_opts, capture_session *cap_session, info_data_t* cap_data, void(*update_cb)(void));
+capture_start(capture_options *capture_opts, GPtrArray *capture_comments,
+              capture_session *cap_session, info_data_t* cap_data,
+              void(*update_cb)(void));
 
 /** Stop a capture session (usually from a menu item). */
 extern void
diff --git a/ui/commandline.c b/ui/commandline.c
index 66a82493ab..66f7ebe111 100644
--- a/ui/commandline.c
+++ b/ui/commandline.c
@@ -173,8 +173,10 @@ commandline_print_usage(gboolean for_help_option) {
     fprintf(output, "\n");
     fprintf(output, "Output:\n");
     fprintf(output, "  -w <outfile|->           set the output filename (or '-' for stdout)\n");
+#ifdef HAVE_LIBPCAP
     fprintf(output, "  --capture-comment <comment>\n");
-    fprintf(output, "                           set the capture file comment, if supported\n");
+    fprintf(output, "                           add a capture file comment, if supported\n");
+#endif
 
     ws_log_print_usage(output);
 
@@ -197,6 +199,7 @@ commandline_print_usage(gboolean for_help_option) {
 }
 
 #define LONGOPT_FULL_SCREEN     LONGOPT_BASE_GUI+1
+#define LONGOPT_CAPTURE_COMMENT LONGOPT_BASE_GUI+2
 
 #define OPTSTRING OPTSTRING_CAPTURE_COMMON OPTSTRING_DISSECT_COMMON "C:g:HhjJ:klm:o:P:r:R:Svw:X:Y:z:"
 static const struct option long_options[] = {
@@ -206,6 +209,7 @@ static const struct option long_options[] = {
         {"display-filter", required_argument, NULL, 'Y' },
         {"version", no_argument, NULL, 'v'},
         {"fullscreen", no_argument, NULL, LONGOPT_FULL_SCREEN },
+        {"capture-comment", required_argument, NULL, LONGOPT_CAPTURE_COMMENT},
         LONGOPT_CAPTURE_COMMON
         LONGOPT_DISSECT_COMMON
         {0, 0, 0, 0 }
@@ -407,6 +411,7 @@ void commandline_other_options(int argc, char *argv[], gboolean opt_reset)
     global_commandline_info.list_link_layer_types = FALSE;
     global_commandline_info.list_timestamp_types = FALSE;
     global_commandline_info.quit_after_cap = getenv("WIRESHARK_QUIT_AFTER_CAPTURE") ? TRUE : FALSE;
+    global_commandline_info.capture_comments = NULL;
 #endif
     global_commandline_info.full_screen = FALSE;
 
@@ -587,6 +592,17 @@ void commandline_other_options(int argc, char *argv[], gboolean opt_reset)
             case LONGOPT_FULL_SCREEN:
                 global_commandline_info.full_screen = TRUE;
                 break;
+#ifdef HAVE_LIBPCAP
+            case LONGOPT_CAPTURE_COMMENT:  /* capture comment */
+                if (global_commandline_info.capture_comments == NULL) {
+                    global_commandline_info.capture_comments = g_ptr_array_new_with_free_func(g_free);
+                }
+                g_ptr_array_add(global_commandline_info.capture_comments, g_strdup(optarg));
+#else
+                capture_option_specified = TRUE;
+                arg_error = TRUE;
+#endif
+                break;
             default:
             case '?':        /* Bad flag - print usage message */
                 arg_error = TRUE;
diff --git a/ui/commandline.h b/ui/commandline.h
index de1ba65528..72eeefc4d7 100644
--- a/ui/commandline.h
+++ b/ui/commandline.h
@@ -27,6 +27,13 @@ typedef struct commandline_param_info
     gboolean list_timestamp_types;
     gboolean start_capture;
     gboolean quit_after_cap;
+
+    /*
+     * We currently don't support this as a way to add file comments
+     * to an existing capture file in Wireshark; we only support it
+     * for adding comments to live captures.
+     */
+    GPtrArray *capture_comments;
 #endif
     e_prefs *prefs_p;
     search_direction jump_backwards;
diff --git a/ui/qt/main.cpp b/ui/qt/main.cpp
index 975c0e21b5..efb55caad6 100644
--- a/ui/qt/main.cpp
+++ b/ui/qt/main.cpp
@@ -1034,7 +1034,9 @@ int main(int argc, char *qt_argv[])
             if (global_capture_opts.ifaces->len == 0)
                 collect_ifaces(&global_capture_opts);
             CaptureFile::globalCapFile()->window = main_w;
-            if (capture_start(&global_capture_opts, main_w->captureSession(), main_w->captureInfoData(), main_window_update)) {
+            if (capture_start(&global_capture_opts, global_commandline_info.capture_comments,
+                              main_w->captureSession(), main_w->captureInfoData(),
+                              main_window_update)) {
                 /* The capture started.  Open stat windows; we do so after creating
                    the main window, to avoid GTK warnings, and after successfully
                    opening the capture file, so we know we have something to compute
diff --git a/ui/qt/main_window_slots.cpp b/ui/qt/main_window_slots.cpp
index eed66d9ad9..0c18aece0d 100644
--- a/ui/qt/main_window_slots.cpp
+++ b/ui/qt/main_window_slots.cpp
@@ -868,7 +868,8 @@ void MainWindow::startCapture() {
 
     CaptureFile::globalCapFile()->window = this;
     info_data_.ui.ui = this;
-    if (capture_start(&global_capture_opts, &cap_session_, &info_data_, main_window_update)) {
+    if (capture_start(&global_capture_opts, NULL, &cap_session_, &info_data_,
+                      main_window_update)) {
         capture_options *capture_opts = cap_session_.capture_opts;
         GString *interface_names;
 
diff --git a/writecap/pcapio.c b/writecap/pcapio.c
index 14e4d7f31b..124531de9c 100644
--- a/writecap/pcapio.c
+++ b/writecap/pcapio.c
@@ -307,7 +307,7 @@ pcapng_write_block(FILE* pfile,
 
 gboolean
 pcapng_write_section_header_block(FILE* pfile,
-                                  const char *comment,
+                                  GPtrArray *comments,
                                   const char *hw,
                                   const char *os,
                                   const char *appname,
@@ -324,13 +324,17 @@ pcapng_write_section_header_block(FILE* pfile,
         block_total_length = sizeof(struct shb) +
                              sizeof(guint32);
         options_length = 0;
-        options_length += pcapng_count_string_option(comment);
+        if (comments != NULL) {
+          for (guint i = 0; i < comments->len; i++) {
+            options_length += pcapng_count_string_option((char *)g_ptr_array_index(comments, i));
+          }
+        }
         options_length += pcapng_count_string_option(hw);
         options_length += pcapng_count_string_option(os);
         options_length += pcapng_count_string_option(appname);
         /* If we have options add size of end-of-options */
         if (options_length != 0) {
-                options_length += (guint32)sizeof(struct option);
+          options_length += (guint32)sizeof(struct option);
         }
         block_total_length += options_length;
 
@@ -345,9 +349,14 @@ pcapng_write_section_header_block(FILE* pfile,
         if (!write_to_file(pfile, (const guint8*)&shb, sizeof(struct shb), bytes_written, err))
                 return FALSE;
 
-        if (!pcapng_write_string_option(pfile, OPT_COMMENT, comment,
-                                        bytes_written, err))
-                return FALSE;
+        if (comments != NULL) {
+          for (guint i = 0; i < comments->len; i++) {
+            if (!pcapng_write_string_option(pfile, OPT_COMMENT,
+                                            (char *)g_ptr_array_index(comments, i),
+                                            bytes_written, err))
+                    return FALSE;
+          }
+        }
         if (!pcapng_write_string_option(pfile, SHB_HARDWARE, hw,
                                         bytes_written, err))
                 return FALSE;
diff --git a/writecap/pcapio.h b/writecap/pcapio.h
index 065e04877b..72df645a76 100644
--- a/writecap/pcapio.h
+++ b/writecap/pcapio.h
@@ -44,8 +44,8 @@ pcapng_write_block(FILE* pfile,
  */
 extern gboolean
 pcapng_write_section_header_block(FILE* pfile,  /**< Write information */
-                                  const char *comment,  /**< Comment on the section, Optinon 1 opt_comment
-                                                         * A UTF-8 string containing a comment that is associated to the current block.
+                                  GPtrArray *comments,  /**< Comments on the section, Optinon 1 opt_comment
+                                                         * UTF-8 strings containing comments that areassociated to the current block.
                                                          */
                                   const char *hw,       /**< HW, Optinon 2 shb_hardware
                                                          * An UTF-8 string containing the description of the hardware  used to create this section.