Move sha1_file_to_archive into libgit

When the specfile (export-subst) attribute was introduced, it added a
dependency from archive-{tar|zip}.c to builtin-archive.c. This broke the
support for archive-operations in libgit.a since builtin-archive.o doesn't
belong in libgit.a.

This patch moves the functions required by libgit.a from builtin-archive.c
to the new file archive.c (which becomes part of libgit.a).

Signed-off-by: Lars Hjemli <hjemli@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

3 files changed, 85 insertions, 81 deletions

diff --git a/Makefile b/Makefile
index 13aa24f91..5aac0c0c8 100644
--- a/Makefile
+++ b/Makefile
@@ -318,7 +318,7 @@ LIB_OBJS = \
 	alloc.o merge-file.o path-list.o help.o unpack-trees.o $(DIFF_OBJS) \
 	color.o wt-status.o archive-zip.o archive-tar.o shallow.o utf8.o \
 	convert.o attr.o decorate.o progress.o mailmap.o symlinks.o remote.o \
-	transport.o bundle.o walker.o parse-options.o ws.o
+	transport.o bundle.o walker.o parse-options.o ws.o archive.o
 
 BUILTIN_OBJS = \
 	builtin-add.o \
diff --git a/archive.c b/archive.c
new file mode 100644
index 000000000..fb159fe59
--- /dev/null
+++ b/archive.c
@@ -0,0 +1,84 @@
+#include "cache.h"
+#include "commit.h"
+#include "attr.h"
+
+static void format_subst(const struct commit *commit,
+                         const char *src, size_t len,
+                         struct strbuf *buf)
+{
+	char *to_free = NULL;
+	struct strbuf fmt;
+
+	if (src == buf->buf)
+		to_free = strbuf_detach(buf, NULL);
+	strbuf_init(&fmt, 0);
+	for (;;) {
+		const char *b, *c;
+
+		b = memmem(src, len, "$Format:", 8);
+		if (!b || src + len < b + 9)
+			break;
+		c = memchr(b + 8, '$', len - 8);
+		if (!c)
+			break;
+
+		strbuf_reset(&fmt);
+		strbuf_add(&fmt, b + 8, c - b - 8);
+
+		strbuf_add(buf, src, b - src);
+		format_commit_message(commit, fmt.buf, buf);
+		len -= c + 1 - src;
+		src  = c + 1;
+	}
+	strbuf_add(buf, src, len);
+	strbuf_release(&fmt);
+	free(to_free);
+}
+
+static int convert_to_archive(const char *path,
+                              const void *src, size_t len,
+                              struct strbuf *buf,
+                              const struct commit *commit)
+{
+	static struct git_attr *attr_export_subst;
+	struct git_attr_check check[1];
+
+	if (!commit)
+		return 0;
+
+	if (!attr_export_subst)
+		attr_export_subst = git_attr("export-subst", 12);
+
+	check[0].attr = attr_export_subst;
+	if (git_checkattr(path, ARRAY_SIZE(check), check))
+		return 0;
+	if (!ATTR_TRUE(check[0].value))
+		return 0;
+
+	format_subst(commit, src, len, buf);
+	return 1;
+}
+
+void *sha1_file_to_archive(const char *path, const unsigned char *sha1,
+                           unsigned int mode, enum object_type *type,
+                           unsigned long *sizep,
+                           const struct commit *commit)
+{
+	void *buffer;
+
+	buffer = read_sha1_file(sha1, type, sizep);
+	if (buffer && S_ISREG(mode)) {
+		struct strbuf buf;
+		size_t size = 0;
+
+		strbuf_init(&buf, 0);
+		strbuf_attach(&buf, buffer, *sizep, *sizep + 1);
+		convert_to_working_tree(path, buf.buf, buf.len, &buf);
+		convert_to_archive(path, buf.buf, buf.len, &buf, commit);
+		buffer = strbuf_detach(&buf, &size);
+		*sizep = size;
+	}
+
+	return buffer;
+}
+
diff --git a/builtin-archive.c b/builtin-archive.c
index 14a1b3077..c2e0c1ea5 100644
--- a/builtin-archive.c
+++ b/builtin-archive.c
@@ -79,86 +79,6 @@ static int run_remote_archiver(const char *remote, int argc,
 	return !!rv;
 }
 
-static void format_subst(const struct commit *commit,
-                         const char *src, size_t len,
-                         struct strbuf *buf)
-{
-	char *to_free = NULL;
-	struct strbuf fmt;
-
-	if (src == buf->buf)
-		to_free = strbuf_detach(buf, NULL);
-	strbuf_init(&fmt, 0);
-	for (;;) {
-		const char *b, *c;
-
-		b = memmem(src, len, "$Format:", 8);
-		if (!b || src + len < b + 9)
-			break;
-		c = memchr(b + 8, '$', len - 8);
-		if (!c)
-			break;
-
-		strbuf_reset(&fmt);
-		strbuf_add(&fmt, b + 8, c - b - 8);
-
-		strbuf_add(buf, src, b - src);
-		format_commit_message(commit, fmt.buf, buf);
-		len -= c + 1 - src;
-		src  = c + 1;
-	}
-	strbuf_add(buf, src, len);
-	strbuf_release(&fmt);
-	free(to_free);
-}
-
-static int convert_to_archive(const char *path,
-                              const void *src, size_t len,
-                              struct strbuf *buf,
-                              const struct commit *commit)
-{
-	static struct git_attr *attr_export_subst;
-	struct git_attr_check check[1];
-
-	if (!commit)
-		return 0;
-
-	if (!attr_export_subst)
-		attr_export_subst = git_attr("export-subst", 12);
-
-	check[0].attr = attr_export_subst;
-	if (git_checkattr(path, ARRAY_SIZE(check), check))
-		return 0;
-	if (!ATTR_TRUE(check[0].value))
-		return 0;
-
-	format_subst(commit, src, len, buf);
-	return 1;
-}
-
-void *sha1_file_to_archive(const char *path, const unsigned char *sha1,
-                           unsigned int mode, enum object_type *type,
-                           unsigned long *sizep,
-                           const struct commit *commit)
-{
-	void *buffer;
-
-	buffer = read_sha1_file(sha1, type, sizep);
-	if (buffer && S_ISREG(mode)) {
-		struct strbuf buf;
-		size_t size = 0;
-
-		strbuf_init(&buf, 0);
-		strbuf_attach(&buf, buffer, *sizep, *sizep + 1);
-		convert_to_working_tree(path, buf.buf, buf.len, &buf);
-		convert_to_archive(path, buf.buf, buf.len, &buf, commit);
-		buffer = strbuf_detach(&buf, &size);
-		*sizep = size;
-	}
-
-	return buffer;
-}
-
 static int init_archiver(const char *name, struct archiver *ar)
 {
 	int rv = -1, i;