apply: fix copy/rename breakage

7ebd52a (Merge branch 'dz/apply-again', 2008-07-01) taught "git-apply" to
grok a (non-git) patch that is a concatenation of separate patches that
touch the same file number of times, by recording the postimage of patch
application of previous round and using it as the preimage for later
rounds.

This "incremental" mode of patch application fundamentally contradicts
with the way git rename/copy patches are designed.  When a git patch talks
about a file A getting modified, and a new file B created out of A, like
this:

	diff --git a/A b/A
	--- a/A
	+++ b/A
	... change text here ...
	diff --git a/A b/B
	copy from A
	copy to B
	--- a/A
	+++ b/B
	... change text here ...

the second change to produce B does not depend on what is done to A with
the first change in any way.  This is explicitly done so for reviewability
of individual patches.

With this commit, we do not look at 'fn_table' that records the postimage
of previous round when applying a patch to produce a new file out of an
existing file.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin-apply.c

@@ -2296,7 +2296,8 @@ static int apply_data(struct patch *patch, struct stat *st, struct cache_entry *
 
 	strbuf_init(&buf, 0);
 
-	if ((tpatch = in_fn_table(patch->old_name)) != NULL) {
+	if (!(patch->is_copy || patch->is_rename) &&
+	    ((tpatch = in_fn_table(patch->old_name)) != NULL)) {
 		if (tpatch == (struct patch *) -1) {
 			return error("patch %s has been renamed/deleted",
 				patch->old_name);
@@ -2375,7 +2376,7 @@ static int verify_index_match(struct cache_entry *ce, struct stat *st)
 static int check_preimage(struct patch *patch, struct cache_entry **ce, struct stat *st)
 {
 	const char *old_name = patch->old_name;
-	struct patch *tpatch;
+	struct patch *tpatch = NULL;
 	int stat_ret = 0;
 	unsigned st_mode = 0;
 
@@ -2389,7 +2390,9 @@ static int check_preimage(struct patch *patch, struct cache_entry **ce, struct s
 		return 0;
 
 	assert(patch->is_new <= 0);
-	if ((tpatch = in_fn_table(old_name)) != NULL) {
+
+	if (!(patch->is_copy || patch->is_rename) &&
+	    (tpatch = in_fn_table(old_name)) != NULL) {
 		if (tpatch == (struct patch *) -1) {
 			return error("%s: has been deleted/renamed", old_name);
 		}
@@ -2399,6 +2402,7 @@ static int check_preimage(struct patch *patch, struct cache_entry **ce, struct s
 		if (stat_ret && errno != ENOENT)
 			return error("%s: %s", old_name, strerror(errno));
 	}
+
 	if (check_index && !tpatch) {
 		int pos = cache_name_pos(old_name, strlen(old_name));
 		if (pos < 0) {

t/t4112-apply-renames.sh

@@ -36,6 +36,9 @@ typedef struct __jmp_buf jmp_buf[1];
 
 #endif /* _SETJMP_H */
 EOF
+cat >klibc/README <<\EOF
+This is a simple readme file.
+EOF
 
 cat >patch <<\EOF
 diff --git a/klibc/arch/x86_64/include/klibc/archsetjmp.h b/include/arch/cris/klibc/archsetjmp.h
@@ -113,6 +116,23 @@ rename to include/arch/m32r/klibc/archsetjmp.h
 
 -#endif /* _SETJMP_H */
 +#endif /* _KLIBC_ARCHSETJMP_H */
+diff --git a/klibc/README b/klibc/README
+--- a/klibc/README
++++ b/klibc/README
+@@ -1,1 +1,4 @@
+ This is a simple readme file.
++And we add a few
++lines at the
++end of it.
+diff --git a/klibc/README b/klibc/arch/README
+copy from klibc/README
+copy to klibc/arch/README
+--- a/klibc/README
++++ b/klibc/arch/README
+@@ -1,1 +1,3 @@
+ This is a simple readme file.
++And we copy it to one level down, and
++add a few lines at the end of it.
 EOF
 
 find klibc -type f -print | xargs git update-index --add --