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[ncplane_putc_yx] copy egc to avoid invalidation

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ncplane_putc_yx() calls ncplane_put() using an EGC extracted
from its nccell argument. The very act of writing that cell
to the plane, however, can grow the plane's underlying EGCpool,
possibly invalidating this reference. This was showing up as
a unit test failure on macOS, and was hopefully also the cause
of unit test failures on Alpine i686. Do a quick heap copy of
the EGC in ncplane_putc_yx(), and free it after writing to the
plane. Shouldn't cost anything (there was no measurable
impact in my testing). Closes #2420.
This commit is contained in:
nick black 2021-12-04 01:02:42 -06:00
parent 418aad1e45
commit 6080de837a
2 changed files with 24 additions and 15 deletions
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23
src/lib/notcurses.c
View File

@ -1434,10 +1434,6 @@ const char* nccell_extended_gcluster(const ncplane* n, const nccell* c){
return egcpool_extended_gcluster(&n->pool, c);
}
const char* cell_extended_gcluster(const struct ncplane* n, const nccell* c){
return nccell_extended_gcluster(n, c);
}
// 'n' ends up above 'above'
int ncplane_move_above(ncplane* restrict n, ncplane* restrict above){
if(n == above){ // probably gets optimized out =/
@ -1685,10 +1681,6 @@ int nccell_load(ncplane* n, nccell* c, const char* gcluster){
return pool_load_direct(&n->pool, c, gcluster, bytes, cols);
}
int cell_load(ncplane* n, nccell* c, const char* gcluster){
return nccell_load(n, c, gcluster);
}
// where the magic happens. write the single EGC completely described by |egc|,
// occupying |cols| columns, to the ncplane |n| at the coordinate |y|, |x|. if
// either or both of |y|/|x| is -1, the current cursor location for that
@ -1782,8 +1774,17 @@ ncplane_put(ncplane* n, int y, int x, const char* egc, int cols,
int ncplane_putc_yx(ncplane* n, int y, int x, const nccell* c){
const int cols = nccell_cols(c);
const char* egc = nccell_extended_gcluster(n, c);
return ncplane_put(n, y, x, egc, cols, c->stylemask, c->channels, strlen(egc));
// unfortunately, |c| comes from |n|. the act of writing |c| to |n| could
// grow |n|'s egcpool, invalidating the reference represented by
// nccell_extended_gcluster(). so we must copy and free it.
char* egc = nccell_strdup(n, c);
if(egc == NULL){
logerror("coudln't duplicate cell\n");
return -1;
}
int r = ncplane_put(n, y, x, egc, cols, c->stylemask, c->channels, strlen(egc));
free(egc);
return r;
}
int ncplane_putegc_yx(ncplane* n, int y, int x, const char* gclust, size_t* sbytes){
@ -2262,7 +2263,7 @@ void ncplane_erase(ncplane* n){
memset(n->fb, 0, sizeof(*n->fb) * n->leny * n->lenx);
egcpool_dump(&n->pool);
egcpool_init(&n->pool);
// we need to zero out the EGC before handing this off to cell_load, but
// we need to zero out the EGC before handing this off to nccell_load, but
// we don't want to lose the channels/attributes, so explicit gcluster load.
n->basecell.gcluster = 0;
nccell_load(n, &n->basecell, egc);

16
src/tests/wide.cpp
View File

@ -986,18 +986,26 @@ TEST_CASE("Wide") {
}
// fill the screen with un-inlineable EGCs
#ifndef __APPLE__ // FIXME
SUBCASE("OfflineEGCs") {
nccell c = NCCELL_TRIVIAL_INITIALIZER;
const char egc[] = u8"\U0001F471\u200D\u2640"; // all one EGC
CHECK(0 < nccell_load(n_, &c, egc));
ncplane_set_scrolling(n_, true);
for(int i = 0 ; i < 100 ; ++i){ // FIXME fill up stdplane
unsigned dimx, dimy;
ncplane_dim_yx(n_, &dimy, &dimx);
unsigned cy;
do{
CHECK(0 < ncplane_putc(n_, &c));
}
unsigned cx;
ncplane_cursor_yx(n_, &cy, &cx);
if(cx + 2 >= dimx){
CHECK(0 < ncplane_putchar(n_, '\n'));
ncplane_cursor_yx(n_, &cy, &cx);
}
}while(cy + 1 < dimy);
nccell_release(n_, &c);
CHECK(0 == notcurses_render(nc_));
}
#endif
SUBCASE("Putwc") {
wchar_t w = L'\u2658';