Readded file-type check at startup

Makefile

@@ -1,6 +1,6 @@
 all: sxiv
 
-VERSION=git-20110404
+VERSION=git-20110405
 
 CC?=gcc
 PREFIX?=/usr/local

image.c

@@ -56,6 +56,23 @@ void img_free(img_t* img) {
 	imlib_free_image();
 }
 
+int img_check(const char *filename) {
+	Imlib_Image *im;
+
+	if (!filename)
+		return 0;
+
+	if ((im = imlib_load_image(filename))) {
+		imlib_context_set_image(im);
+		imlib_image_set_changes_on_disk();
+		imlib_free_image();
+		return 1;
+	} else {
+		warn("invalid file: %s", filename);
+		return 0;
+	}
+}
+
 int img_load(img_t *img, const char *filename) {
 	if (!img || !filename)
 		return 0;
@@ -66,7 +83,7 @@ int img_load(img_t *img, const char *filename) {
 		imlib_context_set_anti_alias(img->aa);
 		img->scalemode = options->scalemode;
 	} else {
-		warn("not an image: %s", filename);
+		warn("invalid file: %s", filename);
 		imlib_context_set_image(im_invalid);
 		imlib_context_set_anti_alias(0);
 	}

main.c

@@ -178,7 +178,7 @@ void update_title() {
 			             fileidx + 1, filecnt, (int) (img.zoom * 100.0), size, unit,
 			             filenames[fileidx]);
 		} else {
-			n = snprintf(win_title, TITLE_LEN, "sxiv: [%d/%d] not an image: %s",
+			n = snprintf(win_title, TITLE_LEN, "sxiv: [%d/%d] invalid: %s",
 			             fileidx + 1, filecnt, filenames[fileidx]);
 		}
 	}
@@ -193,7 +193,13 @@ void update_title() {
 }
 
 int check_append(const char *filename) {
-	if (filename && !access(filename, R_OK)) {
+	if (!filename)
+		return 0;
+
+	if (access(filename, R_OK)) {
+		warn("could not open file: %s", filename);
+		return 0;
+	} else if (img_check(filename)) {
 		if (fileidx == filecnt) {
 			filecnt *= 2;
 			filenames = (const char**) s_realloc(filenames,
@@ -202,7 +208,6 @@ int check_append(const char *filename) {
 		filenames[fileidx++] = filename;
 		return 1;
 	} else {
-		warn("could not open file: %s", filename);
 		return 0;
 	}
 }