make: Fix support for shell paths with spaces

GNU Make incorrectly processes shell paths that contain a space on all
supported platforms. This is a common case on Windows after resolving
the shell's absolute path (e.g. "Documents and Settings" or "Program
Files"). The space is not escaped when constructing the shell command,
and then the shell path is truncated when splitting on the space.

Adding a space to sh_chars causes construct_command_argv_internal to
recurse indefinitely, so instead add a special case when copying the
shell path into the command.

Author: skeeto

Dockerfile

@@ -381,7 +381,9 @@ RUN cat $PREFIX/src/gdb-*.patch | patch -d/gdb-$GDB_VERSION -p1 \
  && cp gdb/.libs/gdb.exe gdbserver/gdbserver.exe $PREFIX/bin/
 
 WORKDIR /make
-RUN /make-$MAKE_VERSION/configure \
+COPY src/make-*.patch $PREFIX/src/
+RUN cat $PREFIX/src/make-*.patch | patch -d/make-$MAKE_VERSION -p1 \
+ && /make-$MAKE_VERSION/configure \
         --host=$ARCH \
         --disable-nls \
         CFLAGS="-std=gnu17 -Os" \

src/make-shell-space.patch

@@ -0,0 +1,21 @@
+Fix support for shell paths containing spaces
+
+GNU Make incorrectly processes shell paths that contain a space on all
+supported platforms. This is a common case on Windows after resolving
+the shell's absolute path (e.g. "Documents and Settings" or "Program
+Files"). The space is not escaped when constructing the shell command,
+and then the shell path is truncated when splitting on the space.
+
+Adding a space to sh_chars causes construct_command_argv_internal to
+recurse indefinitely, so instead add a special case when copying the
+shell path into the command.
+
+--- a/src/job.c
++++ b/src/job.c
+@@ -3474,5 +3474,5 @@
+     for (cp = shell; *cp != '\0'; ++cp)
+       {
+-        if (strchr (sh_chars, *cp) != 0)
++        if (strchr (sh_chars, *cp) != 0 || ISSPACE (*cp))
+           *(ap++) = '\\';
+         *(ap++) = *cp;