commit 76cdb7b52505c1c8713932b6571b85dbecda943f
author Sam Lantinga <slouken@libsdl.org> Tue Oct 20 11:51:23 2020 -0700
committer Sam Lantinga <slouken@libsdl.org> Tue Oct 20 11:51:23 2020 -0700
tree 9237e29b0d69c3f015c68e1d24062d508f91ca88
parent 5b623b3bfc3067a410fef530e8f1787ad0c55bee

Fixed bug 5323 - SDL_SetWindowMaximumSize fails if Width or Height is equal to minimum Height or Width

batyastudios

Basicly there is problem and somewhat a solution: https://discourse.libsdl.org/t/setwindowmaximumsize-bug/28267

If you SDL_SetWindowMaximumSize() after SDL_SetWindowMinimumSize() with one of axes have the same value, function will have no effect.

This: (line 2144@SDL_video.c)
if (max_w <= window->min_w || max_h <= window->min_h) {
    SDL_SetError("SDL_SetWindowMaximumSize(): Tried to set maximum size smaller than minimum size");
    return;
}

May be changed to this:
if (max_w < window->min_w || max_h < window->min_h) {
    SDL_SetError("SDL_SetWindowMaximumSize(): Tried to set maximum size smaller than minimum size");
    return;
}

src/video/SDL_video.c

diff --git a/src/video/SDL_video.c b/src/video/SDL_video.c
index 36d42ce..3980e26 100644
--- a/src/video/SDL_video.c
+++ b/src/video/SDL_video.c
@@ -2152,8 +2152,8 @@
         return;
     }
 
-    if ((window->max_w && min_w >= window->max_w) ||
-        (window->max_h && min_h >= window->max_h)) {
+    if ((window->max_w && min_w > window->max_w) ||
+        (window->max_h && min_h > window->max_h)) {
         SDL_SetError("SDL_SetWindowMinimumSize(): Tried to set minimum size larger than maximum size");
         return;
     }
@@ -2195,7 +2195,7 @@
         return;
     }
 
-    if (max_w <= window->min_w || max_h <= window->min_h) {
+    if (max_w < window->min_w || max_h < window->min_h) {
         SDL_SetError("SDL_SetWindowMaximumSize(): Tried to set maximum size smaller than minimum size");
         return;
     }