archive: rename attribute specfile to export-subst

As suggested by Junio and Johannes, change the name of the former
attribute specfile to export-subst to indicate its function rather
than purpose and to make clear that it is not applied to working tree
files.

Signed-off-by: Rene Scharfe <rene.scharfe@lsrfire.ath.cx>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/gitattributes.txt

@@ -424,10 +424,10 @@ frotz	unspecified
 Creating an archive
 ~~~~~~~~~~~~~~~~~~~
 
-`specfile`
-^^^^^^^^^^
+`export-subst`
+^^^^^^^^^^^^^^
 
-If the attribute `specfile` is set for a file then git will expand
+If the attribute `export-subst` is set for a file then git will expand
 several placeholders when adding this file to an archive.  The
 expansion depends on the availability of a commit ID, i.e. if
 gitlink:git-archive[1] has been given a tree instead of a commit or a

builtin-archive.c

@@ -81,8 +81,8 @@ static int run_remote_archiver(const char *remote, int argc,
 	return !!rv;
 }
 
-static void *format_specfile(const struct commit *commit, const char *format,
-                             unsigned long *sizep)
+static void *format_subst(const struct commit *commit, const char *format,
+                          unsigned long *sizep)
 {
 	unsigned long len = *sizep, result_len = 0;
 	const char *a = format;
@@ -131,22 +131,22 @@ static void *convert_to_archive(const char *path,
                                 const void *src, unsigned long *sizep,
                                 const struct commit *commit)
 {
-	static struct git_attr *attr_specfile;
+	static struct git_attr *attr_export_subst;
 	struct git_attr_check check[1];
 
 	if (!commit)
 		return NULL;
 
-        if (!attr_specfile)
-                attr_specfile = git_attr("specfile", 8);
+        if (!attr_export_subst)
+                attr_export_subst = git_attr("export-subst", 12);
 
-	check[0].attr = attr_specfile;
+	check[0].attr = attr_export_subst;
 	if (git_checkattr(path, ARRAY_SIZE(check), check))
 		return NULL;
 	if (!ATTR_TRUE(check[0].value))
 		return NULL;
 
-	return format_specfile(commit, src, sizep);
+	return format_subst(commit, src, sizep);
 }
 
 void *sha1_file_to_archive(const char *path, const unsigned char *sha1,

t/t5000-tar-tree.sh

@@ -28,15 +28,15 @@ commit id embedding:
 TAR=${TAR:-tar}
 UNZIP=${UNZIP:-unzip}
 
-SPECFILEFORMAT=%H%n
+SUBSTFORMAT=%H%n
 
 test_expect_success \
     'populate workdir' \
     'mkdir a b c &&
      echo simple textfile >a/a &&
      mkdir a/bin &&
      cp /bin/sh a/bin &&
-     printf "A\$Format:%s\$O" "$SPECFILEFORMAT" >a/specfile &&
+     printf "A\$Format:%s\$O" "$SUBSTFORMAT" >a/substfile &&
      ln -s a a/l1 &&
      (p=long_path_to_a_file && cd a &&
       for depth in 1 2 3 4 5; do mkdir $p && cd $p; done &&
@@ -108,20 +108,20 @@ test_expect_success \
     'diff -r a c/prefix/a'
 
 test_expect_success \
-    'create an archive with a specfile' \
-    'echo specfile specfile >a/.gitattributes &&
+    'create an archive with a substfile' \
+    'echo substfile export-subst >a/.gitattributes &&
      git archive HEAD >f.tar &&
      rm a/.gitattributes'
 
 test_expect_success \
-    'extract specfile' \
+    'extract substfile' \
     '(mkdir f && cd f && $TAR xf -) <f.tar'
 
 test_expect_success \
-     'validate specfile contents' \
-     'git log --max-count=1 "--pretty=format:A${SPECFILEFORMAT}O" HEAD \
-      >f/a/specfile.expected &&
-      diff f/a/specfile.expected f/a/specfile'
+     'validate substfile contents' \
+     'git log --max-count=1 "--pretty=format:A${SUBSTFORMAT}O" HEAD \
+      >f/a/substfile.expected &&
+      diff f/a/substfile.expected f/a/substfile'
 
 test_expect_success \
     'git archive --format=zip' \