static link projectM runtime on win64, drop band aid dll bundle

build/Makefile

@@ -977,21 +977,14 @@ WIN64_DIR     = $(BUILDS_ROOT)/desktop-win64
 WIN64_TARGET  = $(WIN64_DIR)/theseus.exe
 WIN64_CXX     = x86_64-w64-mingw32-g++
 
-# mingw runtime DLLs. The Theseus exe is -static-libgcc -static-libstdc++,
-# but libprojectM-4.dll (cross-built without those flags) drags libgcc_s_seh
-# and libstdc++-6 in at load time. Ship all three alongside the exe.
-# On macOS/Homebrew these live in x86_64-w64-mingw32/bin/; on Linux/APT they
-# live in x86_64-w64-mingw32/lib/. Try bin/ first, fall back to lib/.
-define find_mingw_dll
-$(shell \
+# libwinpthread-1.dll: still a runtime dep even with -static-libgcc/stdc++
+# because mingw-w64's posix thread model links winpthread dynamically.
+# macOS/Homebrew puts it in x86_64-w64-mingw32/bin/; Linux/APT in lib/.
+WIN64_PTHREAD_DLL := $(shell \
   BASE=$$(dirname $$(dirname $$(realpath $$(which x86_64-w64-mingw32-gcc 2>/dev/null)))) ; \
-  BIN=$$BASE/x86_64-w64-mingw32/bin/$(1) ; \
-  LIB=$$BASE/x86_64-w64-mingw32/lib/$(1) ; \
+  BIN=$$BASE/x86_64-w64-mingw32/bin/libwinpthread-1.dll ; \
+  LIB=$$BASE/x86_64-w64-mingw32/lib/libwinpthread-1.dll ; \
   if [ -f "$$BIN" ]; then echo $$BIN ; elif [ -f "$$LIB" ]; then echo $$LIB ; fi)
-endef
-WIN64_PTHREAD_DLL := $(call find_mingw_dll,libwinpthread-1.dll)
-WIN64_GCC_DLL     := $(call find_mingw_dll,libgcc_s_seh-1.dll)
-WIN64_STDCPP_DLL  := $(call find_mingw_dll,libstdc++-6.dll)
 
 SDL2_MINGW_DIR    ?= $(HOME)/cross/sdl2-mingw
 SDL2_MINGW_INC    = $(SDL2_MINGW_DIR)/SDL2-2.32.10/x86_64-w64-mingw32/include
@@ -1184,8 +1177,6 @@ $(WIN64_TARGET): $(WIN64_OBJS)
 	@cp $(SDL2_MINGW_BIN)/SDL2.dll $(WIN64_DIR)/
 	@cp $(MIXER_MINGW_BIN)/SDL2_mixer.dll $(WIN64_DIR)/
 	@cp $(WIN64_PTHREAD_DLL) $(WIN64_DIR)/
-	@if [ -n "$(WIN64_GCC_DLL)"    ]; then cp $(WIN64_GCC_DLL)    $(WIN64_DIR)/ ; fi
-	@if [ -n "$(WIN64_STDCPP_DLL)" ]; then cp $(WIN64_STDCPP_DLL) $(WIN64_DIR)/ ; fi
 	@if [ -f $(MPV_MINGW_DIR)/libmpv-2.dll ]; then cp $(MPV_MINGW_DIR)/libmpv-2.dll $(WIN64_DIR)/; fi
 	@for f in $(CURL_MINGW_DIR)/bin/libcurl*.dll $(CURL_MINGW_DIR)/libcurl*.dll; do \
 		[ -f "$$f" ] && cp "$$f" $(WIN64_DIR)/ || true ; \

build/cmake-toolchains/mingw-w64-x86_64.cmake

@@ -23,6 +23,20 @@ set(CMAKE_RC_COMPILER       ${MINGW_TRIPLE}-windres)
 set(CMAKE_AR                ${MINGW_TRIPLE}-ar)
 set(CMAKE_RANLIB            ${MINGW_TRIPLE}-ranlib)
 
+# Static-link the gcc + stdc++ runtime into every output shared lib so
+# libprojectM-4.dll and libprojectM-4-playlist.dll have no load-time
+# dependency on libgcc_s_seh-1.dll / libstdc++-6.dll. Eliminates the
+# class of ABI mismatch that hits when Windows resolves a different
+# libstdc++-6.dll from PATH than the one the DLL was built against.
+set(CMAKE_C_FLAGS_INIT             "-static-libgcc")
+set(CMAKE_CXX_FLAGS_INIT           "-static-libgcc -static-libstdc++")
+# -Wl,--exclude-libs=ALL keeps the statically-linked runtime symbols
+# (_Unwind_Resume, __cxa_throw, etc.) internal to the DLL. Without it
+# the import lib re-exports them and any consumer that also -static-
+# linkages the same runtime hits multiple-definition errors.
+set(CMAKE_SHARED_LINKER_FLAGS_INIT "-static-libgcc -static-libstdc++ -Wl,--exclude-libs=libgcc.a:libgcc_eh.a:libstdc++.a")
+set(CMAKE_EXE_LINKER_FLAGS_INIT    "-static-libgcc -static-libstdc++")
+
 # Look for headers/libs in the mingw sysroot, not the host system. The
 # sysroot path varies by distro; cmake walks the compiler's default
 # search path so an explicit CMAKE_FIND_ROOT_PATH usually isn't needed,