fbsplash: reinstate drawing of over/undersized images; shrink

Based on the patch by Nuno Lucas <ntlucas@gmail.com>

function                                             old     new   delta
fbsplash_main                                        938     864     -74

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

diff --git a/miscutils/fbsplash.c b/miscutils/fbsplash.c
index 3bf16ab..5974006 100644 (file)
--- a/miscutils/fbsplash.c
+++ b/miscutils/fbsplash.c
@@ -84,7 +84,7 @@ static void fb_open(const char *strfb_device)
        // map the device in memory
        G.addr = mmap(NULL,
                        G.scr_var.xres * G.scr_var.yres
-                       * BYTES_PER_PIXEL /*(G.scr_var.bits_per_pixel / 8)*/ ,
+                       * BYTES_PER_PIXEL /*(G.scr_var.bits_per_pixel / 8)*/,
                        PROT_WRITE, MAP_SHARED, fbfd, 0);
        if (G.addr == MAP_FAILED)
                bb_perror_msg_and_die("mmap");
@@ -121,7 +121,7 @@ static void fb_drawrectangle(void)
        // vertical lines
        ptr1 = (DATA*)(G.addr + (G.nbar_posy * G.scr_var.xres + G.nbar_posx) * BYTES_PER_PIXEL);
        ptr2 = (DATA*)(G.addr + (G.nbar_posy * G.scr_var.xres + G.nbar_posx + G.nbar_width - 1) * BYTES_PER_PIXEL);
-       cnt = G.nbar_height - 1 /* HUH?!  G.nbar_posy + G.nbar_height - 1 - G.nbar_posy*/;
+       cnt = G.nbar_height - 1;
        do {
                *ptr1 = thispix; ptr1 += G.scr_var.xres;
                *ptr2 = thispix; ptr2 += G.scr_var.xres;
@@ -216,70 +216,69 @@ static void fb_drawprogressbar(unsigned percent)
  */
 static void fb_drawimage(void)
 {
-       char *head, *ptr;
        FILE *theme_file;
+       char *read_ptr;
        unsigned char *pixline;
        unsigned i, j, width, height, line_size;
 
-       if (LONE_DASH(G.image_filename))
+       if (LONE_DASH(G.image_filename)) {
                theme_file = stdin;
-       else {
+       } else {
                int fd = open_zipped(G.image_filename);
                if (fd < 0)
                        bb_simple_perror_msg_and_die(G.image_filename);
                theme_file = xfdopen_for_read(fd);
        }
-       head = xmalloc(256);
 
-       /* parse ppm header
-        * - A ppm image’s magic number is the two characters "P6".
+       /* Parse ppm header:
+        * - Magic: two characters "P6".
         * - Whitespace (blanks, TABs, CRs, LFs).
         * - A width, formatted as ASCII characters in decimal.
         * - Whitespace.
-        * - A height, again in ASCII decimal.
+        * - A height, ASCII decimal.
         * - Whitespace.
-        * - The maximum color value (Maxval), again in ASCII decimal. Must be
-        *   less than 65536.
+        * - The maximum color value, ASCII decimal, in 0..65535
         * - Newline or other single whitespace character.
+        *   (we support newline only)
         * - A raster of Width * Height pixels in triplets of rgb
-        *   in pure binary by 1 (or not implemented 2) bytes.
+        *   in pure binary by 1 or 2 bytes. (we support only 1 byte)
         */
+#define concat_buf bb_common_bufsiz1
+       read_ptr = concat_buf;
        while (1) {
-               if (fgets(head, 256, theme_file) == NULL
-                       /* do not overrun the buffer */
-                       || strlen(bb_common_bufsiz1) >= sizeof(bb_common_bufsiz1) - 256)
+               int w, h, max_color_val;
+               int rem = concat_buf + sizeof(concat_buf) - read_ptr;
+               if (rem < 2
+                || fgets(read_ptr, rem, theme_file) == NULL
+               ) {
                        bb_error_msg_and_die("bad PPM file '%s'", G.image_filename);
-
-               ptr = memchr(skip_whitespace(head), '#', 256);
-               if (ptr != NULL)
-                       *ptr = 0; /* ignore comments */
-               strcat(bb_common_bufsiz1, head);
-               // width, height, max_color_val
-               if (sscanf(bb_common_bufsiz1, "P6 %u %u %u", &width, &height, &i) == 3
-                       && i <= 255)
+               }
+               read_ptr = strchrnul(read_ptr, '#');
+               *read_ptr = '\0'; /* ignore #comments */
+               if (sscanf(concat_buf, "P6 %u %u %u", &w, &h, &max_color_val) == 3
+                && max_color_val <= 255
+               ) {
+                       width = w; /* w is on stack, width may be in register */
+                       height = h;
                        break;
-               /* If we do not find a signature throughout the whole file then
-                  we will diagnose this via EOF on read in the head of the loop.  */
+               }
        }
 
-       if (ENABLE_FEATURE_CLEAN_UP)
-               free(head);
-       if (width != G.scr_var.xres || height != G.scr_var.yres)
-               bb_error_msg_and_die("PPM %dx%d does not match screen %dx%d",
-                                                        width, height, G.scr_var.xres, G.scr_var.yres);
        line_size = width*3;
+       pixline = xmalloc(line_size);
+
        if (width > G.scr_var.xres)
                width = G.scr_var.xres;
        if (height > G.scr_var.yres)
                height = G.scr_var.yres;
-
-       pixline = xmalloc(line_size);
        for (j = 0; j < height; j++) {
-               unsigned char *pixel = pixline;
-               DATA *src = (DATA *)(G.addr + j * G.scr_fix.line_length);
+               unsigned char *pixel;
+               DATA *src;
 
                if (fread(pixline, 1, line_size, theme_file) != line_size)
                        bb_error_msg_and_die("bad PPM file '%s'", G.image_filename);
+               pixel = pixline;
+               src = (DATA *)(G.addr + j * G.scr_fix.line_length);
                for (i = 0; i < width; i++) {
                        unsigned thispix;
                        thispix = (((unsigned)pixel[0] << 8) & 0xf800)
@@ -289,8 +288,7 @@ static void fb_drawimage(void)
                        pixel += 3;
                }
        }
-       if (ENABLE_FEATURE_CLEAN_UP)
-               free(pixline);
+       free(pixline);
        fclose(theme_file);
 }
 
@@ -312,7 +310,7 @@ static void init(const char *cfg_filename)
        char *token[2];
        parser_t *parser = config_open2(cfg_filename, xfopen_stdin);
        while (config_read(parser, token, 2, 2, "#=",
-                                   (PARSE_NORMAL | PARSE_MIN_DIE) & ~(PARSE_TRIM | PARSE_COLLAPSE))) {
+                               (PARSE_NORMAL | PARSE_MIN_DIE) & ~(PARSE_TRIM | PARSE_COLLAPSE))) {
                unsigned val = xatoi_u(token[1]);
                int i = index_in_strings(param_names, token[0]);
                if (i < 0)