Fixed subst.mk not to corrupt files

Up to now, using subst.mk may have led to file corruption during active
package development. This happened when a sed(1) command had a syntax
error, in which case the whole sed(1) command was terminated, leaving an
empty original file behind.

This commit changes that behavior by applying the sed(1) commands to
the original file and saving the result in a temporary file. Only
after that succeeded is the original file overwritten.

During this rewrite, SUBST_POSTCMD has been removed, since it was
only used in one place (mk/wrapper), and since it relied on the exact
sequence of the internal commands. No package in either main pkgsrc
or pkgsrc-wip uses this variable right now.

0 files changed, 0 insertions, 0 deletions