Fix [17960b80db]: Missing libtcl?.?.dll.a in Cygwin

changes

@@ -9467,3 +9467,5 @@ Many code fixes to avoid overflow or undefined behavior.  Thanks chrstphrchvz.
 	=> platform 1.1.1
 
 2026-08-10 tzdata updated to Olson's tzdata2026c (nijtmans)
+
+2026-08-28 Missing libtcl?.?.dll.a in Cygwin (nijtmans)

unix/configure

@@ -6783,7 +6783,7 @@ fi
 	    ;;
 	CYGWIN_*|MINGW32_*|MSYS_*)
 	    SHLIB_CFLAGS="-fno-common"
-	    SHLIB_LD='${CC} -shared'
+	    SHLIB_LD='${CC} -shared -Wl,--out-implib,$(patsubst %.dll,%.dll.a,${LIB_FILE})'
 	    SHLIB_SUFFIX=".dll"
 	    DL_OBJS="tclLoadDl.o"
 	    PLAT_OBJS='${CYGWIN_OBJS}'
@@ -19104,6 +19104,9 @@ fi
 TCL_UNSHARED_LIB_SUFFIX=${UNSHARED_LIB_SUFFIX}
 TCL_SHARED_LIB_SUFFIX=${SHARED_LIB_SUFFIX}
 eval "TCL_LIB_FILE=libtcl${LIB_SUFFIX}"
+if test "$ac_cv_cygwin" = "yes" -a "$SHARED_BUILD" != "0"; then
+EXTRA_INSTALL_BINARIES='$(INSTALL_LIBRARY) $(patsubst %.dll,%.dll.a,${LIB_FILE}) "$(LIB_INSTALL_DIR)"'
+fi
 
 # tclConfig.sh needs a version of the _LIB_SUFFIX that has been eval'ed
 # since on some platforms TCL_LIB_FILE contains shell escapes.

unix/configure.in

@@ -767,6 +767,9 @@ fi
 TCL_UNSHARED_LIB_SUFFIX=${UNSHARED_LIB_SUFFIX}
 TCL_SHARED_LIB_SUFFIX=${SHARED_LIB_SUFFIX}
 eval "TCL_LIB_FILE=libtcl${LIB_SUFFIX}"
+if test "$ac_cv_cygwin" = "yes" -a "$SHARED_BUILD" != "0"; then
+EXTRA_INSTALL_BINARIES='$(INSTALL_LIBRARY) $(patsubst %.dll,%.dll.a,${LIB_FILE}) "$(LIB_INSTALL_DIR)"'
+fi
 
 # tclConfig.sh needs a version of the _LIB_SUFFIX that has been eval'ed
 # since on some platforms TCL_LIB_FILE contains shell escapes.

unix/tcl.m4

@@ -1185,7 +1185,7 @@ AC_DEFUN([SC_CONFIG_CFLAGS], [
 	    ;;
 	CYGWIN_*|MINGW32_*|MSYS_*)
 	    SHLIB_CFLAGS="-fno-common"
-	    SHLIB_LD='${CC} -shared'
+	    SHLIB_LD='${CC} -shared -Wl,--out-implib,$(patsubst %.dll,%.dll.a,${LIB_FILE})'
 	    SHLIB_SUFFIX=".dll"
 	    DL_OBJS="tclLoadDl.o"
 	    PLAT_OBJS='${CYGWIN_OBJS}'