refactor duplicated fill_mm() in checkout and merge-recursive

The following function is duplicated:

  fill_mm

Move it to xdiff-interface.c and rename it 'read_mmblob', as suggested
by Junio C Hamano.

Also, change parameters order for consistency with read_mmfile().

Signed-off-by: Michael Lukashov <michael.lukashov@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin-checkout.c

@@ -128,24 +128,6 @@ static int checkout_stage(int stage, struct cache_entry *ce, int pos,
 		     (stage == 2) ? "our" : "their");
 }
 
-/* NEEDSWORK: share with merge-recursive */
-static void fill_mm(const unsigned char *sha1, mmfile_t *mm)
-{
-	unsigned long size;
-	enum object_type type;
-
-	if (!hashcmp(sha1, null_sha1)) {
-		mm->ptr = xstrdup("");
-		mm->size = 0;
-		return;
-	}
-
-	mm->ptr = read_sha1_file(sha1, &type, &size);
-	if (!mm->ptr || type != OBJ_BLOB)
-		die("unable to read blob object %s", sha1_to_hex(sha1));
-	mm->size = size;
-}
-
 static int checkout_merged(int pos, struct checkout *state)
 {
 	struct cache_entry *ce = active_cache[pos];
@@ -163,9 +145,9 @@ static int checkout_merged(int pos, struct checkout *state)
 	    ce_stage(active_cache[pos+2]) != 3)
 		return error("path '%s' does not have all 3 versions", path);
 
-	fill_mm(active_cache[pos]->sha1, &ancestor);
+	read_mmblob(&ancestor, active_cache[pos]->sha1);
-	fill_mm(active_cache[pos+1]->sha1, &ours);
+	read_mmblob(&ours, active_cache[pos+1]->sha1);
-	fill_mm(active_cache[pos+2]->sha1, &theirs);
+	read_mmblob(&theirs, active_cache[pos+2]->sha1);
 
 	status = ll_merge(&result_buf, path, &ancestor,
 			  &ours, "ours", &theirs, "theirs", 0);

merge-recursive.c

@@ -599,23 +599,6 @@ struct merge_file_info
 		 merge:1;
 };
 
-static void fill_mm(const unsigned char *sha1, mmfile_t *mm)
-{
-	unsigned long size;
-	enum object_type type;
-
-	if (!hashcmp(sha1, null_sha1)) {
-		mm->ptr = xstrdup("");
-		mm->size = 0;
-		return;
-	}
-
-	mm->ptr = read_sha1_file(sha1, &type, &size);
-	if (!mm->ptr || type != OBJ_BLOB)
-		die("unable to read blob object %s", sha1_to_hex(sha1));
-	mm->size = size;
-}
-
 static int merge_3way(struct merge_options *o,
 		      mmbuffer_t *result_buf,
 		      struct diff_filespec *one,
@@ -653,9 +636,9 @@ static int merge_3way(struct merge_options *o,
 		name2 = xstrdup(mkpath("%s", branch2));
 	}
 
-	fill_mm(one->sha1, &orig);
+	read_mmblob(&orig, one->sha1);
-	fill_mm(a->sha1, &src1);
+	read_mmblob(&src1, a->sha1);
-	fill_mm(b->sha1, &src2);
+	read_mmblob(&src2, b->sha1);
 
 	merge_status = ll_merge(result_buf, a->path, &orig,
 				&src1, name1, &src2, name2,

xdiff-interface.c

@@ -218,6 +218,23 @@ int read_mmfile(mmfile_t *ptr, const char *filename)
 	return 0;
 }
 
+void read_mmblob(mmfile_t *ptr, const unsigned char *sha1)
+{
+	unsigned long size;
+	enum object_type type;
+
+	if (!hashcmp(sha1, null_sha1)) {
+		ptr->ptr = xstrdup("");
+		ptr->size = 0;
+		return;
+	}
+
+	ptr->ptr = read_sha1_file(sha1, &type, &size);
+	if (!ptr->ptr || type != OBJ_BLOB)
+		die("unable to read blob object %s", sha1_to_hex(sha1));
+	ptr->size = size;
+}
+
 #define FIRST_FEW_BYTES 8000
 int buffer_is_binary(const char *ptr, unsigned long size)
 {

xdiff-interface.h

@@ -18,6 +18,7 @@ int parse_hunk_header(char *line, int len,
 		      int *ob, int *on,
 		      int *nb, int *nn);
 int read_mmfile(mmfile_t *ptr, const char *filename);
+void read_mmblob(mmfile_t *ptr, const unsigned char *sha1);
 int buffer_is_binary(const char *ptr, unsigned long size);
 
 extern void xdiff_set_find_func(xdemitconf_t *xecfg, const char *line, int cflags);