text_file: allocate line buffers dynamically

Use a single GString buffer object in all functions loading the
database.  Enlarge it automatically for long lines.  This eliminates
the maximum line length for tag values.  There is still an upper limit
of 512 kB to prevent denial of service, but that's reasonable I guess.

1 files changed, 15 insertions, 16 deletions

diff --git a/src/song_save.c b/src/song_save.c
index b18057201..4b8409d86 100644
--- a/src/song_save.c
+++ b/src/song_save.c
@@ -21,8 +21,8 @@
 #include "song.h"
 #include "tag_save.h"
 #include "directory.h"
-#include "path.h"
 #include "tag.h"
+#include "text_file.h"
 
 #include <glib.h>
 
@@ -117,32 +117,31 @@ parse_tag_value(char *buffer, enum tag_type *type_r)
 
 bool
 songvec_load(FILE *fp, struct songvec *sv, struct directory *parent,
-	     GError **error_r)
+	     GString *buffer, GError **error_r)
 {
-	char buffer[MPD_PATH_MAX + 1024];
+	char *line;
 	struct song *song = NULL;
 	enum tag_type type;
 	const char *value;
 
-	while (fgets(buffer, sizeof(buffer), fp) &&
-	       !g_str_has_prefix(buffer, SONG_END)) {
-		g_strchomp(buffer);
+	while ((line = read_text_line(fp, buffer)) != NULL &&
+	       !g_str_has_prefix(line, SONG_END)) {
 
-		if (0 == strncmp(SONG_KEY, buffer, strlen(SONG_KEY))) {
+		if (0 == strncmp(SONG_KEY, line, strlen(SONG_KEY))) {
 			if (song)
 				commit_song(sv, song);
 
-			song = song_file_new(buffer + strlen(SONG_KEY),
+			song = song_file_new(line + strlen(SONG_KEY),
 					     parent);
-		} else if (*buffer == 0) {
+		} else if (*line == 0) {
 			/* ignore empty lines (starting with '\0') */
 		} else if (song == NULL) {
 			g_set_error(error_r, song_save_quark(), 0,
 				    "Problems reading song info");
 			return false;
-		} else if (0 == strncmp(SONG_FILE, buffer, strlen(SONG_FILE))) {
+		} else if (0 == strncmp(SONG_FILE, line, strlen(SONG_FILE))) {
 			/* we don't need this info anymore */
-		} else if ((value = parse_tag_value(buffer,
+		} else if ((value = parse_tag_value(line,
 						    &type)) != NULL) {
 			if (!song->tag) {
 				song->tag = tag_new();
@@ -150,18 +149,18 @@ songvec_load(FILE *fp, struct songvec *sv, struct directory *parent,
 			}
 
 			tag_add_item(song->tag, type, value);
-		} else if (0 == strncmp(SONG_TIME, buffer, strlen(SONG_TIME))) {
+		} else if (0 == strncmp(SONG_TIME, line, strlen(SONG_TIME))) {
 			if (!song->tag) {
 				song->tag = tag_new();
 				tag_begin_add(song->tag);
 			}
 
-			song->tag->time = atoi(&(buffer[strlen(SONG_TIME)]));
-		} else if (0 == strncmp(SONG_MTIME, buffer, strlen(SONG_MTIME))) {
-			song->mtime = atoi(&(buffer[strlen(SONG_MTIME)]));
+			song->tag->time = atoi(&(line[strlen(SONG_TIME)]));
+		} else if (0 == strncmp(SONG_MTIME, line, strlen(SONG_MTIME))) {
+			song->mtime = atoi(&(line[strlen(SONG_MTIME)]));
 		} else {
 			g_set_error(error_r, song_save_quark(), 0,
-				    "unknown line in db: %s", buffer);
+				    "unknown line in db: %s", line);
 			return false;
 		}
 	}