Read width and height from jpeg, png and gif files directly instead of executing w3mimgdisplay -size.

image.c

@@ -625,6 +625,91 @@ getImage(Image * image, ParsedURL *current, int flag)
     return cache;
 }
 
+static int
+parseImageHeader(char *path, u_int *width, u_int *height)
+{
+    char *suffix;
+
+    suffix = path + strlen(path);
+    if (strcasecmp(suffix - 5, ".jpeg") == 0 || strcasecmp(suffix - 4 , ".jpg") == 0) {
+	FILE *fp = fopen(path, "r");
+	if (fp) {
+	    u_char buf[2];
+	    if (fread(buf, 1, 2, fp) != 2 || memcmp(buf, "\xff\xd8", 2) != 0 ||
+	        fseek(fp, 2, SEEK_CUR) < 0)	/* 0xffe0 */
+		goto  jpg_error;
+
+	    while (fread(buf, 1, 2, fp) == 2) {
+		size_t len = ((buf[0] << 8) | buf[1]) - 2;
+		if (fseek(fp, len, SEEK_CUR) < 0) goto jpg_error;
+	        if (fread(buf, 1, 2, fp) == 2 && memcmp(buf, "\xff\xc0", 2) == 0) {
+		    fseek(fp, 3, SEEK_CUR);
+		    if (fread(buf, 1, 2, fp) == 2) {
+			*height = (buf[0] << 8) | buf[1];
+			if (fread(buf, 1, 2, fp) == 2) {
+			    *width = (buf[0] << 8) | buf[1];
+			    fclose(fp);
+			    return TRUE;
+			}
+		    }
+		    break;
+		}
+	    }
+
+	jpg_error:
+	    fclose(fp);
+	    return FALSE;
+	}
+    }
+    else if (strcasecmp(suffix - 4,  ".png") == 0) {
+	FILE *fp = fopen(path, "r");
+	if (fp) {
+	    u_char buf[8];
+	    if (fread(buf, 1, 8, fp) != 8 ||
+	        memcmp(buf, "\x89\x50\x4e\x47\x0d\x0a\x1a\x0a", 8) != 0 ||
+		fseek(fp, 8, SEEK_CUR) < 0)
+		goto  png_error;
+
+	    if (fread(buf, 1, 4, fp) == 4) {
+	        *width = (buf[0] << 24) | (buf[1] << 16) | (buf[2] << 8) | buf[3];
+		if (fread(buf, 1, 4, fp) == 4) {
+		    *height = (buf[0] << 24) | (buf[1] << 16) | (buf[2] << 8) | buf[3];
+		    fclose(fp);
+		    return TRUE;
+		}
+	    }
+
+	png_error:
+	    fclose(fp);
+	    return FALSE;
+	}
+    }
+    else if (strcasecmp(suffix - 4, ".gif") == 0) {
+	FILE *fp = fopen(path, "r");
+	if (fp) {
+	    u_char buf[3];
+	    if (fread(buf, 1, 3, fp) != 3 || memcmp(buf, "GIF", 3) != 0 ||
+	        fseek(fp, 3, SEEK_CUR) < 0) {
+		goto  png_error;
+	    }
+	    if (fread(buf, 1, 2, fp) == 2) {
+		*width = (buf[1] << 8) | buf[0];
+		if (fread(buf, 1, 2, fp) == 2) {
+		    *height = (buf[1] << 8) | buf[0];
+		    fclose(fp);
+		    return TRUE;
+		}
+	    }
+	}
+
+	gif_error:
+	    fclose(fp);
+	    return FALSE;
+    }
+
+    return FALSE;
+}
+
 int
 getImageSize(ImageCache * cache)
 {
@@ -637,6 +722,10 @@ getImageSize(ImageCache * cache)
     if (!cache || !(cache->loaded & IMG_FLAG_LOADED) ||
 	(cache->width > 0 && cache->height > 0))
 	return FALSE;
+
+    if (parseImageHeader(cache->file, &w, &h))
+	goto got_image_size;
+
     tmp = Strnew();
     if (!strchr(Imgdisplay, '/'))
 	Strcat_m_charp(tmp, w3m_auxbin_dir(), "/", NULL);
@@ -652,6 +741,8 @@ getImageSize(ImageCache * cache)
 
     if (!(w > 0 && h > 0))
 	return FALSE;
+
+got_image_size:
     w = (int)(w * image_scale / 100 + 0.5);
     if (w == 0)
 	w = 1;