diff options
| -rw-r--r-- | src/vcr.c | 21 |
1 files changed, 17 insertions, 4 deletions
@@ -1347,10 +1347,7 @@ void vcr_clear_row(vcr_t *vcr, vcr_layer_t layer, int row, int x, int width) } -/* copy what's below a given row up the specified amount across all the layers */ -/* XXX: note for now we expect (and assert) rows == 1, to simplify TYPE_MEM, - * this is acceptable for all existing call sites - */ +/* copy what's below a given row up by one row across all the layers */ void vcr_shift_below_row_up_one(vcr_t *vcr, int row) { assert(vcr); @@ -1391,6 +1388,22 @@ void vcr_shift_below_row_up_one(vcr_t *vcr, int row) uint8_t *src = &vcr->mem.bits[(1 + row) * VCR_ROW_HEIGHT * vcr->mem.pitch]; size_t len = ((1 + *(vcr->hierarchy_end_ptr)) - (1 + row)) * VCR_ROW_HEIGHT * vcr->mem.pitch; + assert(*(vcr->hierarchy_end_ptr) >= row); + + /* (hierarchy_end * VCR_ROW_HEIGHT) may overflow vcr->height, as it's not kept clipped. + * It more represents where the process hierarchy virtually ends - which may or may not stay within + * the chart's allocated area. So len must be clamped here to ensure we're not attempting + * to copy out of bounds. + */ + len = MIN(len, &vcr->mem.bits[vcr->height * vcr->mem.pitch] - src); + + assert(src + len <= vcr->mem.bits + vcr->mem.pitch * vcr->height); + assert(dest + len <= vcr->mem.bits + vcr->mem.pitch * vcr->height); + + /* XXX the xlib backend enjoys some luxuries in dealing with clipping that must be dealt with manually here, + * and that just hasn't been entirely fleshed out beyond "do enough to at least not segfault" + */ + memmove(dest, src, len); break; } |