fix: -Wsign-compare warnings (#336)

mixing signed and unsigned types in comparison can end up having
unintended results. for example:

	if (-1 < 1U)
		printf("true\n");
	else
		printf("false\n");

previously we silenced these warnings, instead just fix them properly
via necessary casting, and in cases where the value cannot be negative
(e.g width/height members) make them unsigned.

Reviewed-on: https://codeberg.org/nsxiv/nsxiv/pulls/336
Reviewed-by: explosion-mental <explosion-mental@noreply.codeberg.org>

7 files changed, 30 insertions, 28 deletions

diff --git a/.woodpecker/CFLAGS b/.woodpecker/CFLAGS
index df24be7..57d7d16 100644
--- a/.woodpecker/CFLAGS
+++ b/.woodpecker/CFLAGS
@@ -10,4 +10,4 @@
 -Wbad-function-cast -Wdeclaration-after-statement
 -Wmissing-prototypes -Wstrict-prototypes
 # silence
--Wno-sign-compare -Wno-unused-parameter -Wno-missing-field-initializers
+-Wno-unused-parameter -Wno-missing-field-initializers
diff --git a/commands.c b/commands.c
index 8741a26..762fc05 100644
--- a/commands.c
+++ b/commands.c
@@ -36,7 +36,7 @@ bool cg_quit(arg_t status)
 	unsigned int i;
 
 	if (options->to_stdout && markcnt > 0) {
-		for (i = 0; i < filecnt; i++) {
+		for (i = 0; i < (unsigned int)filecnt; i++) {
 			if (files[i].flags & FF_MARK)
 				printf("%s%c", files[i].name, options->using_null ? '\0' : '\n');
 		}
@@ -319,7 +319,7 @@ bool ci_drag(arg_t drag_mode)
 	float px, py;
 	XEvent e;
 
-	if ((int)(img.w * img.zoom) <= win.w && (int)(img.h * img.zoom) <= win.h)
+	if ((int)(img.w * img.zoom) <= (int)win.w && (int)(img.h * img.zoom) <= (int)win.h)
 		return false;
 
 	win_set_cursor(&win, drag_mode == DRAG_ABSOLUTE ? CURSOR_DRAG_ABSOLUTE : CURSOR_DRAG_RELATIVE);
diff --git a/image.c b/image.c
index 434b645..beedcbd 100644
--- a/image.c
+++ b/image.c
@@ -473,7 +473,7 @@ bool img_load(img_t *img, const fileinfo_t *file)
 
 CLEANUP void img_close(img_t *img, bool decache)
 {
-	int i;
+	unsigned int i;
 
 	if (img->multi.cnt > 0) {
 		for (i = 0; i < img->multi.cnt; i++) {
@@ -671,7 +671,9 @@ bool img_zoom_to(img_t *img, float z)
 	int x, y;
 	if (ZOOM_MIN <= z && z <= ZOOM_MAX) {
 		win_cursor_pos(img->win, &x, &y);
-		if (x < 0 || x >= img->win->w || y < 0 || y >= img->win->h) {
+		if (x < 0 || (unsigned int)x >= img->win->w ||
+		    y < 0 || (unsigned int)y >= img->win->h)
+		{
 			x = img->win->w / 2;
 			y = img->win->h / 2;
 		}
@@ -688,13 +690,13 @@ bool img_zoom_to(img_t *img, float z)
 
 bool img_zoom(img_t *img, int d)
 {
-	int i = d > 0 ? 0 : ARRLEN(zoom_levels)-1;
-	while (i >= 0 && i < ARRLEN(zoom_levels) && (d > 0 ?
-	       zoom_levels[i]/100 <= img->zoom : zoom_levels[i]/100 >= img->zoom))
+	int i = d > 0 ? 0 : (int)ARRLEN(zoom_levels)-1;
+	while (i >= 0 && i < (int)ARRLEN(zoom_levels) &&
+	       (d > 0 ? zoom_levels[i]/100 <= img->zoom : zoom_levels[i]/100 >= img->zoom))
 	{
 		i += d;
 	}
-	i = MIN(MAX(i, 0), ARRLEN(zoom_levels)-1);
+	i = MIN(MAX(i, 0), (int)ARRLEN(zoom_levels)-1);
 	return img_zoom_to(img, zoom_levels[i]/100);
 }
 
@@ -787,7 +789,7 @@ bool img_pan_edge(img_t *img, direction_t dir)
 
 void img_rotate(img_t *img, degree_t d)
 {
-	int i, tmp;
+	unsigned int i, tmp;
 	float ox, oy;
 
 	imlib_context_set_image(img->im);
@@ -816,7 +818,7 @@ void img_rotate(img_t *img, degree_t d)
 
 void img_flip(img_t *img, flipdir_t d)
 {
-	int i;
+	unsigned int i;
 	void (*imlib_flip_op[3])(void) = {
 		imlib_image_flip_horizontal,
 		imlib_image_flip_vertical,
@@ -878,7 +880,7 @@ bool img_change_gamma(img_t *img, int d)
 
 static bool img_frame_goto(img_t *img, int n)
 {
-	if (n < 0 || n >= img->multi.cnt || n == img->multi.sel)
+	if (n < 0 || (unsigned int)n >= img->multi.cnt || (unsigned int)n == img->multi.sel)
 		return false;
 
 	img->multi.sel = n;
@@ -899,7 +901,7 @@ bool img_frame_navigate(img_t *img, int d)
 		return false;
 
 	d += img->multi.sel;
-	d = MAX(0, MIN(d, img->multi.cnt - 1));
+	d = MAX(0, MIN(d, (int)img->multi.cnt - 1));
 
 	return img_frame_goto(img, d);
 }
diff --git a/main.c b/main.c
index a6c4187..877870e 100644
--- a/main.c
+++ b/main.c
@@ -224,7 +224,7 @@ static bool check_timeouts(int *t)
 	int i = 0, tdiff, tmin = -1;
 	struct timeval now;
 
-	while (i < ARRLEN(timeouts)) {
+	while (i < (int)ARRLEN(timeouts)) {
 		if (timeouts[i].active) {
 			gettimeofday(&now, 0);
 			tdiff = TV_DIFF(&timeouts[i].when, &now);
@@ -434,11 +434,11 @@ int nav_button(void)
 
 	win_cursor_pos(&win, &x, &y);
 	nw = NAV_IS_REL ? win.w * NAV_WIDTH / 100 : NAV_WIDTH;
-	nw = MIN(nw, (win.w + 1) / 2);
+	nw = MIN(nw, ((int)win.w + 1) / 2);
 
 	if (x < nw)
 		return 0;
-	else if (x < win.w-nw)
+	else if (x < (int)win.w - nw)
 		return 1;
 	else
 		return 2;
@@ -917,7 +917,7 @@ int main(int argc, char *argv[])
 		const char *name[] = { "image-info", "thumb-info", "key-handler", "win-title" };
 		const char *s = "/nsxiv/exec/";
 
-		for (i = 0; i < ARRLEN(cmd); i++) {
+		for (i = 0; i < (int)ARRLEN(cmd); i++) {
 			n = strlen(homedir) + strlen(dsuffix) + strlen(s) + strlen(name[i]) + 1;
 			cmd[i]->cmd = emalloc(n);
 			snprintf(cmd[i]->cmd, n, "%s%s%s%s", homedir, dsuffix, s, name[i]);
diff --git a/nsxiv.h b/nsxiv.h
index 7d81fff..4f903e9 100644
--- a/nsxiv.h
+++ b/nsxiv.h
@@ -162,9 +162,9 @@ typedef struct {
 
 typedef struct {
 	img_frame_t *frames;
-	int cap;
-	int cnt;
-	int sel;
+	unsigned int cap;
+	unsigned int cnt;
+	unsigned int sel;
 	bool animate;
 	unsigned int framedelay;
 	int length;
@@ -403,8 +403,8 @@ struct win {
 	unsigned int bw;
 
 	struct {
-		int w;
-		int h;
+		unsigned int w;
+		unsigned int h;
 		Pixmap pm;
 	} buf;
 
diff --git a/thumbs.c b/thumbs.c
index 8341014..a0b1063 100644
--- a/thumbs.c
+++ b/thumbs.c
@@ -561,7 +561,7 @@ bool tns_zoom(tns_t *tns, int d)
 	oldzl = tns->zl;
 	tns->zl += -(d < 0) + (d > 0);
 	tns->zl = MAX(tns->zl, 0);
-	tns->zl = MIN(tns->zl, ARRLEN(thumb_sizes)-1);
+	tns->zl = MIN(tns->zl, (int)ARRLEN(thumb_sizes)-1);
 
 	tns->bw = ((thumb_sizes[tns->zl] - 1) >> 5) + 1;
 	tns->bw = MIN(tns->bw, 4);
diff --git a/window.c b/window.c
index 19875e3..9bbfbf9 100644
--- a/window.c
+++ b/window.c
@@ -259,7 +259,7 @@ void win_open(win_t *win)
 	             ButtonReleaseMask | ButtonPressMask | KeyPressMask |
 	             PointerMotionMask | StructureNotifyMask);
 
-	for (i = 0; i < ARRLEN(cursors); i++) {
+	for (i = 0; i < (int)ARRLEN(cursors); i++) {
 		if (i != CURSOR_NONE)
 			cursors[i].icon = XCreateFontCursor(e->dpy, cursors[i].name);
 	}
@@ -274,12 +274,12 @@ void win_open(win_t *win)
 	n = icons[ARRLEN(icons)-1].size;
 	icon_data = emalloc((n * n + 2) * sizeof(*icon_data));
 
-	for (i = 0; i < ARRLEN(icons); i++) {
+	for (i = 0; i < (int)ARRLEN(icons); i++) {
 		n = 0;
 		icon_data[n++] = icons[i].size;
 		icon_data[n++] = icons[i].size;
 
-		for (j = 0; j < icons[i].cnt; j++) {
+		for (j = 0; j < (int)icons[i].cnt; j++) {
 			for (c = icons[i].data[j] >> 4; c >= 0; c--)
 				icon_data[n++] = icon_colors[icons[i].data[j] & 0x0F];
 		}
@@ -345,7 +345,7 @@ bool win_configure(win_t *win, XConfigureEvent *c)
 {
 	bool changed;
 
-	changed = win->w != c->width || win->h + win->bar.h != c->height;
+	changed = win->w != (unsigned int)c->width || win->h + win->bar.h != (unsigned int)c->height;
 
 	win->x = c->x;
 	win->y = c->y;
@@ -516,7 +516,7 @@ void win_set_title(win_t *win, const char *title, size_t len)
 {
 	int i, targets[] = { ATOM_WM_NAME, ATOM_WM_ICON_NAME, ATOM__NET_WM_NAME, ATOM__NET_WM_ICON_NAME };
 
-	for (i = 0; i < ARRLEN(targets); ++i) {
+	for (i = 0; i < (int)ARRLEN(targets); ++i) {
 		XChangeProperty(win->env.dpy, win->xwin, atoms[targets[i]],
 		                atoms[ATOM_UTF8_STRING], 8, PropModeReplace,
 		                (unsigned char *)title, len);