winetricks: workaround missing /usr/bin/wine64

See discussion in https://bugs.debian.org/1031649.

src/winetricks

@@ -5089,10 +5089,31 @@ winetricks_set_wineprefix()
         elif command -v "${WINE}64" >/dev/null 2>&1; then
             WINE64="${WINE}64"
         else
-            # Handle case where wine binaries (or binary wrappers) have a suffix
-            WINE64="$(dirname "${WINE}")/"
-            [ "${WINE64}" = "./" ] && WINE64=""
-            WINE64="${WINE64}$(basename "${WINE}" | sed 's/^wine/wine64/')"
+            # wineboot often is a link next to wineserver (whose path we already know)
+            # pointing to wineapploader in Wine's bindir. So try this to figure out Wine's bindir.
+            WINEBOOT_BIN="$(echo "${WINESERVER_BIN}"|sed 's,wineserver,wineboot,')"
+            if [ -x "${WINEBOOT_BIN}" ]; then
+                if [ -n "${READLINK_F}" ]; then
+                    true
+                elif [ "$(uname -s)" = "Darwin" ]; then
+                    # readlink exists on MacOS, but does not support "-f" on MacOS < 12.3
+                    # Use perl instead
+                    READLINK_F="perl -MCwd=abs_path -le 'print abs_path readlink(shift);'"
+                else
+                    READLINK_F="readlink -f"
+                fi
+                WINE_BINDIR="$(dirname "$(${READLINK_F} "${WINEBOOT_BIN}" 2>/dev/null)" 2>/dev/null)"
+                if [ -x "${WINE_BINDIR}/wine64" ]; then
+                    # Workaround case where wine and related binaries are in path,
+                    # but wine64 is only in Wine's bindir
+                    WINE64="${WINE_BINDIR}/wine64"
+                fi
+            else
+                # Handle case where wine binaries (or binary wrappers) have a suffix
+                WINE64="$(dirname "${WINE}")/"
+                [ "${WINE64}" = "./" ] && WINE64=""
+                WINE64="${WINE64}$(basename "${WINE}" | sed 's/^wine/wine64/')"
+            fi
         fi
         WINE_ARCH="${WINE64}"
         WINE_MULTI="${WINE}"