input/vcd: do propagate parse error in file header

The vcd input module's parse_header() routine used the 'status' variable
in inappropriate ways. It was preset to false, then raised when the end
of the header was seen, and lowered when parse errors occurred. This made
parse errors go unnoticed because the flag always was raised at the end
of the header. The issue was introduced in commit 0ab36d2f5448.

Separate the "header seen" from "header valid" aspects. The "header seen"
is needed for loop control including resource management. The "valid" is
needed to propagate errors should they have happened at any time during
parsing.

Also adjust the process_buffer() and end() routines to cease processing
the input file's content after header parsing failed earlier. Which
addresses bug #1758 for VCD.

diff --git a/src/input/vcd.c b/src/input/vcd.c
index acd30e5d7f05ae91420453b221f7b4176d111a69..1064ad6a33ddc3e72599f2bc12826a73f840b32f 100644 (file)
--- a/src/input/vcd.c
+++ b/src/input/vcd.c
@@ -1176,7 +1176,7 @@ static gboolean check_header_in_reread(const struct sr_input *in)
 static int parse_header(const struct sr_input *in, GString *buf)
 {
        struct context *inc;
-       gboolean status;
+       gboolean enddef_seen, header_valid;
        char *name, *contents;
        size_t size;
        int ret;
@@ -1184,34 +1184,35 @@ static int parse_header(const struct sr_input *in, GString *buf)
        inc = in->priv;
 
        /* Parse sections until complete header was seen. */
-       status = FALSE;
+       enddef_seen = FALSE;
+       header_valid = TRUE;
        name = contents = NULL;
        inc->conv_bits.max_bits = 1;
        while (parse_section(buf, &name, &contents)) {
                sr_dbg("Section '%s', contents '%s'.", name, contents);
 
                if (g_strcmp0(name, "enddefinitions") == 0) {
-                       status = TRUE;
+                       enddef_seen = TRUE;
                        goto done_section;
                }
                if (g_strcmp0(name, "timescale") == 0) {
                        if (parse_timescale(inc, contents) != SR_OK)
-                               status = FALSE;
+                               header_valid = FALSE;
                        goto done_section;
                }
                if (g_strcmp0(name, "scope") == 0) {
                        if (parse_scope(inc, contents, FALSE) != SR_OK)
-                               status = FALSE;
+                               header_valid = FALSE;
                        goto done_section;
                }
                if (g_strcmp0(name, "upscope") == 0) {
                        if (parse_scope(inc, NULL, TRUE) != SR_OK)
-                               status = FALSE;
+                               header_valid = FALSE;
                        goto done_section;
                }
                if (g_strcmp0(name, "var") == 0) {
                        if (parse_header_var(inc, contents) != SR_OK)
-                               status = FALSE;
+                               header_valid = FALSE;
                        goto done_section;
                }
 
@@ -1221,14 +1222,14 @@ done_section:
                g_free(contents);
                contents = NULL;
 
-               if (status)
+               if (enddef_seen)
                        break;
        }
        g_free(name);
        g_free(contents);
 
-       inc->got_header = status;
-       if (!status)
+       inc->got_header = enddef_seen && header_valid;
+       if (!inc->got_header)
                return SR_ERR_DATA;
 
        /* Create sigrok channels here, late, logic before analog. */
@@ -2008,6 +2009,9 @@ static int process_buffer(struct sr_input *in, gboolean is_eof)
 
        inc = in->priv;
 
+       if (!inc->got_header)
+               return SR_ERR_DATA;
+
        /* Send feed header and samplerate (once) before sample data. */
        if (!inc->started) {
                std_session_send_df_header(in->sdi);
@@ -2168,11 +2172,14 @@ static int end(struct sr_input *in)
                ret = SR_OK;
 
        /* Flush most recently queued sample data when EOF is seen. */
-       count = inc->data_after_timestamp ? 1 : 0;
-       add_samples(in, count, TRUE);
+       if (inc->got_header && ret == SR_OK) {
+               count = inc->data_after_timestamp ? 1 : 0;
+               add_samples(in, count, TRUE);
+       }
 
        /* Optionally suggest downsampling after all input data was seen. */
-       (void)ts_stats_post(inc, !inc->data_after_timestamp);
+       if (inc->got_header)
+               (void)ts_stats_post(inc, !inc->data_after_timestamp);
 
        /* Must send DF_END when DF_HEADER was sent before. */
        if (inc->started)