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formats/td0_dsk.cpp: Don't swallow bits and bytes at the end of Huffman-encoded images, when the word buffer can no longer be filled

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AJR 2023-09-08 23:14:00 -04:00
parent 40590f79b9
commit f7ad1b7474
1 changed files with 14 additions and 13 deletions
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19
src/lib/formats/td0_dsk.cpp
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@ -90,7 +90,7 @@ private:
uint8_t getlen; uint8_t getlen;
int data_read(uint8_t *buf, uint16_t size); int data_read(uint8_t *buf, uint16_t size);
int next_word(); int next_word(int needed);
int GetBit(); int GetBit();
int GetByte(); int GetByte();
void StartHuff(); void StartHuff();
@ -412,16 +412,15 @@ static const uint8_t d_len[256] = {
0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08,
}; };
int td0dsk_t::next_word() int td0dsk_t::next_word(int needed)
{
if(tdctl.ibufndx >= tdctl.ibufcnt)
{ {
while (getlen <= 8) { // typically reads a word at a time
if(tdctl.ibufndx >= tdctl.ibufcnt) {
tdctl.ibufndx = 0; tdctl.ibufndx = 0;
tdctl.ibufcnt = data_read(tdctl.inbuf,BUFSZ); tdctl.ibufcnt = data_read(tdctl.inbuf,BUFSZ);
if(tdctl.ibufcnt <= 0) if(tdctl.ibufcnt <= 0)
return(-1); return(getlen >= needed ? 0 : -1);
} }
while (getlen <= 8) { // typically reads a word at a time
getbuf |= tdctl.inbuf[tdctl.ibufndx++] << (8 - getlen); getbuf |= tdctl.inbuf[tdctl.ibufndx++] << (8 - getlen);
getlen += 8; getlen += 8;
} }
@ -432,7 +431,7 @@ int td0dsk_t::next_word()
int td0dsk_t::GetBit() /* get one bit */ int td0dsk_t::GetBit() /* get one bit */
{ {
int16_t i; int16_t i;
if(next_word() < 0) if(next_word(1) < 0)
return(-1); return(-1);
i = getbuf; i = getbuf;
getbuf <<= 1; getbuf <<= 1;
@ -446,7 +445,7 @@ int td0dsk_t::GetBit() /* get one bit */
int td0dsk_t::GetByte() /* get a byte */ int td0dsk_t::GetByte() /* get a byte */
{ {
uint16_t i; uint16_t i;
if(next_word() != 0) if(next_word(8) != 0)
return(-1); return(-1);
i = getbuf; i = getbuf;
getbuf <<= 8; getbuf <<= 8;
@ -1031,7 +1030,9 @@ bool td0_format::load(util::random_read &io, uint32_t form_factor, const std::ve
else else
build_pc_track_mfm(track, head, image, base_cell_count*2, track_spt, sects, calc_default_pc_gap3_size(form_factor, sects[0].actual_size)); build_pc_track_mfm(track, head, image, base_cell_count*2, track_spt, sects, calc_default_pc_gap3_size(form_factor, sects[0].actual_size));
track_spt = offset < actual ? imagebuf[offset] : 255; if(actual <= offset)
return false;
track_spt = imagebuf[offset];
} }
if((track_count > 50) && (form_factor == floppy_image::FF_525)) // ? if((track_count > 50) && (form_factor == floppy_image::FF_525)) // ?
{ {