Re: [TESTCASE] Failing 'git am' when core.autocrlf=true

Linus Torvalds [off-list ref] writes:

And the reason is really interesting: it only happens if the index file 
has the same date as the entry in the index, in which case we end up doign 
the "careful" check in ce_smudge_racily_clean_entry() and there the 
"ce_modified_check_fs()" will end up re-reading the file, and if we don't 
have the right CRLF behaviour, we will now return DATA_CHANGED.

So the call-chain for this is:

	cmd_write_tree ->
	  write_tree ->
	    write_index ->
	      ce_smudge_racily_clean_entry -> 
		ce_modified_check_fs ->
		  ce_compare_data ->
		    index_fd ->
		      convert_to_git ->
			** wrong answer unless auto_crlf is set **

		and now "ce_smudge_racily_clean_entry()" will do
			ce->ce_size = htonl(0);

and the one-liner fix I sent out is actually the right fix.

This was harder to find than it should have been, because it actually 
depends on the datestamp of the index file matching the datestamp of the 
file in question!

Ahhhh, I forgot that we made write-tree to write back into index
because at that point we have a fully populated cache-tree.

Your analysis makes sense to me.  Thanks.