blame: move textconv_object with related functions

textconv_object is used in places other than blame.c and should be moved
to a more appropriate location.  Other textconv related functions are
located in diff.c so that seems as good a place as any.

Signed-off-by: Jeff Smith <whydoubt@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin.h

@@ -25,8 +25,6 @@ struct fmt_merge_msg_opts {
 extern int fmt_merge_msg(struct strbuf *in, struct strbuf *out,
 			 struct fmt_merge_msg_opts *);
 
-extern int textconv_object(const char *path, unsigned mode, const struct object_id *oid, int oid_valid, char **buf, unsigned long *buf_size);
-
 extern int is_builtin(const char *s);
 
 extern int cmd_add(int argc, const char **argv, const char *prefix);

builtin/blame.c

@@ -146,34 +146,6 @@ static int diff_hunks(mmfile_t *file_a, mmfile_t *file_b,
 	return xdi_diff(file_a, file_b, &xpp, &xecfg, &ecb);
 }
 
-/*
- * Prepare diff_filespec and convert it using diff textconv API
- * if the textconv driver exists.
- * Return 1 if the conversion succeeds, 0 otherwise.
- */
-int textconv_object(const char *path,
-		    unsigned mode,
-		    const struct object_id *oid,
-		    int oid_valid,
-		    char **buf,
-		    unsigned long *buf_size)
-{
-	struct diff_filespec *df;
-	struct userdiff_driver *textconv;
-
-	df = alloc_filespec(path);
-	fill_filespec(df, oid->hash, oid_valid, mode);
-	textconv = get_textconv(df);
-	if (!textconv) {
-		free_filespec(df);
-		return 0;
-	}
-
-	*buf_size = fill_textconv(textconv, df, buf);
-	free_filespec(df);
-	return 1;
-}
-
 /*
  * Given an origin, prepare mmfile_t structure to be used by the
  * diff machinery

builtin/cat-file.c

@@ -5,6 +5,7 @@
  */
 #include "cache.h"
 #include "builtin.h"
+#include "diff.h"
 #include "parse-options.h"
 #include "userdiff.h"
 #include "streaming.h"

diff.c

@@ -5270,6 +5270,29 @@ size_t fill_textconv(struct userdiff_driver *driver,
 	return size;
 }
 
+int textconv_object(const char *path,
+		    unsigned mode,
+		    const struct object_id *oid,
+		    int oid_valid,
+		    char **buf,
+		    unsigned long *buf_size)
+{
+	struct diff_filespec *df;
+	struct userdiff_driver *textconv;
+
+	df = alloc_filespec(path);
+	fill_filespec(df, oid->hash, oid_valid, mode);
+	textconv = get_textconv(df);
+	if (!textconv) {
+		free_filespec(df);
+		return 0;
+	}
+
+	*buf_size = fill_textconv(textconv, df, buf);
+	free_filespec(df);
+	return 1;
+}
+
 void setup_diff_pager(struct diff_options *opt)
 {
 	/*

diff.h

@@ -385,6 +385,13 @@ extern size_t fill_textconv(struct userdiff_driver *driver,
  */
 extern struct userdiff_driver *get_textconv(struct diff_filespec *one);
 
+/*
+ * Prepare diff_filespec and convert it using diff textconv API
+ * if the textconv driver exists.
+ * Return 1 if the conversion succeeds, 0 otherwise.
+ */
+extern int textconv_object(const char *path, unsigned mode, const struct object_id *oid, int oid_valid, char **buf, unsigned long *buf_size);
+
 extern int parse_rename_score(const char **cp_p);
 
 extern long parse_algorithm_value(const char *value);