Fix "prefer download" behavior

When this was first implemented the assumption was that a downloaded dive
that is to be merged with an existing dive would have the same time stamp.
But as Linus pointed out even back then, this does fail if a dive has been
merged with a download from a different dive computer before (think:
download from computer a, then download same dive from b, then improve
something in the parsing from computer a and try to redownload; the time
stamp could have changed).

This commit also fixes a silly omission in the merge_dives() function
(which ended up ALWAYS prefering the downloaded dive) and finally
implements the necessary changes to mark dives downloaded from a Uemis SDA
as well.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>

dive.c

@@ -1077,8 +1077,6 @@ struct dive *try_to_merge(struct dive *a, struct dive *b, gboolean prefer_downlo
 	 */
 	if ((a->when >= b->when + 60) || (a->when <= b->when - 60))
 		return NULL;
-	if (prefer_downloaded && a->when != b->when)
-		return NULL;
 	if (!prefer_downloaded) {
 		/* Dive 'a' is 'offset' seconds before dive 'b' */
 		offset = find_sample_offset(a, b);
@@ -1093,10 +1091,12 @@ struct dive *merge_dives(struct dive *a, struct dive *b, int offset, gboolean pr
 	struct dive *res = alloc_dive();
 	struct dive *dl = NULL;
 
-	if (a->downloaded)
-		dl = a;
-	else if (b->downloaded)
-		dl = b;
+	if (prefer_downloaded) {
+		if (a->downloaded)
+			dl = a;
+		else if (b->downloaded)
+			dl = b;
+	}
 	res->when = a->when;
 	res->selected = a->selected || b->selected;
 	merge_trip(res, a, b);

dive.h

@@ -392,7 +392,7 @@ static inline struct dive *get_dive(int nr)
 	for ((_i) = 0; ((_x) = get_dive(_i)) != NULL; (_i)++)
 
 extern void parse_xml_init(void);
-extern void parse_xml_buffer(const char *url, const char *buf, int size, GError **error);
+extern void parse_xml_buffer(const char *url, const char *buf, int size, gboolean downloaded, GError **error);
 extern void parse_xml_exit(void);
 extern void set_filename(const char *filename, gboolean force);
 

file.c

@@ -72,7 +72,7 @@ static void suunto_read(struct zip_file *file, GError **error)
 		size = read * 3 / 2;
 		mem = realloc(mem, size);
 	}
-	parse_xml_buffer(_("SDE file"), mem, read, error);
+	parse_xml_buffer(_("SDE file"), mem, read, FALSE, error);
 	free(mem);
 }
 #endif
@@ -246,7 +246,7 @@ static void parse_file_buffer(const char *filename, struct memblock *mem, GError
 	if (fmt && open_by_filename(filename, fmt+1, mem, error))
 		return;
 
-	parse_xml_buffer(filename, mem->buffer, mem->size, error);
+	parse_xml_buffer(filename, mem->buffer, mem->size, FALSE, error);
 }
 
 void parse_file(const char *filename, GError **error, gboolean possible_default_filename)

gtk-gui.c

@@ -1685,7 +1685,7 @@ static GError *setup_uemis_import(device_data_t *data)
 #if UEMIS_DEBUG > 3
 		fprintf(debugfile, "xml buffer \"%s\"\n\n", buf);
 #endif
-		parse_xml_buffer("Uemis Download", buf, strlen(buf), &error);
+		parse_xml_buffer("Uemis Download", buf, strlen(buf), TRUE, &error);
 		set_uemis_last_dive(uemis_max_dive_data);
 #if UEMIS_DEBUG > 2
 		fprintf(debugfile, "uemis_max_dive_data: %s\n", uemis_max_dive_data);

parse-xml.c

@@ -168,6 +168,7 @@ static struct {
 } cur_event;
 static struct tm cur_tm;
 static int cur_cylinder_index, cur_ws_index;
+static gboolean from_download;
 
 static enum import_source {
 	UNKNOWN,
@@ -1219,6 +1220,7 @@ static void dive_start(void)
 		add_dive_to_trip(cur_dive, cur_trip);
 		cur_dive->tripflag = IN_TRIP;
 	}
+	cur_dive->downloaded = from_download;
 }
 
 static void dive_end(void)
@@ -1499,9 +1501,10 @@ static void reset_all(void)
 	import_source = UNKNOWN;
 }
 
-void parse_xml_buffer(const char *url, const char *buffer, int size, GError **error)
+void parse_xml_buffer(const char *url, const char *buffer, int size, gboolean downloaded, GError **error)
 {
 	xmlDoc *doc;
+	from_download = downloaded;
 
 	doc = xmlReadMemory(buffer, size, url, NULL, 0);
 	if (!doc) {