Merge branch 'es/format-patch-interdiff-cleanup'

"format-patch --range-diff=<prev> <origin>..HEAD" has been taught
not to ignore <origin> when <prev> is a single version.

* es/format-patch-interdiff-cleanup:
  format-patch: use 'origin' as start of current-series-range when known
  diff-lib: tighten show_interdiff()'s interface
  diff: move show_interdiff() from its own file to diff-lib

Author: gitster

Makefile

@@ -889,7 +889,6 @@ LIB_OBJS += hashmap.o
 LIB_OBJS += help.o
 LIB_OBJS += hex.o
 LIB_OBJS += ident.o
-LIB_OBJS += interdiff.o
 LIB_OBJS += json-writer.o
 LIB_OBJS += kwset.o
 LIB_OBJS += levenshtein.o

builtin/log.c

@@ -33,7 +33,6 @@
 #include "commit-slab.h"
 #include "repository.h"
 #include "commit-reach.h"
-#include "interdiff.h"
 #include "range-diff.h"
 
 #define MAIL_DEFAULT_WRAP 72
@@ -1207,7 +1206,8 @@ static void make_cover_letter(struct rev_info *rev, int use_stdout,
 
 	if (rev->idiff_oid1) {
 		fprintf_ln(rev->diffopt.file, "%s", rev->idiff_title);
-		show_interdiff(rev, 0);
+		show_interdiff(rev->idiff_oid1, rev->idiff_oid2, 0,
+			       &rev->diffopt);
 	}
 
 	if (rev->rdiff1) {
@@ -1595,16 +1595,20 @@ static void infer_range_diff_ranges(struct strbuf *r1,
 				    struct commit *head)
 {
 	const char *head_oid = oid_to_hex(&head->object.oid);
+	int prev_is_range = !!strstr(prev, "..");
 
-	if (!strstr(prev, "..")) {
+	if (prev_is_range)
+		strbuf_addstr(r1, prev);
+	else
 		strbuf_addf(r1, "%s..%s", head_oid, prev);
+
+	if (origin)
+		strbuf_addf(r2, "%s..%s", oid_to_hex(&origin->object.oid), head_oid);
+	else if (prev_is_range)
+		die(_("failed to infer range-diff origin of current series"));
+	else {
+		warning(_("using '%s' as range-diff origin of current series"), prev);
 		strbuf_addf(r2, "%s..%s", prev, head_oid);
-	} else if (!origin) {
-		die(_("failed to infer range-diff ranges"));
-	} else {
-		strbuf_addstr(r1, prev);
-		strbuf_addf(r2, "%s..%s",
-			    oid_to_hex(&origin->object.oid), head_oid);
 	}
 }
 

diff-lib.c

@@ -565,3 +565,28 @@ int index_differs_from(struct repository *r,
 	object_array_clear(&rev.pending);
 	return (rev.diffopt.flags.has_changes != 0);
 }
+
+static struct strbuf *idiff_prefix_cb(struct diff_options *opt, void *data)
+{
+	return data;
+}
+
+void show_interdiff(const struct object_id *oid1, const struct object_id *oid2,
+		    int indent, struct diff_options *diffopt)
+{
+	struct diff_options opts;
+	struct strbuf prefix = STRBUF_INIT;
+
+	memcpy(&opts, diffopt, sizeof(opts));
+	opts.output_format = DIFF_FORMAT_PATCH;
+	opts.output_prefix = idiff_prefix_cb;
+	strbuf_addchars(&prefix, ' ', indent);
+	opts.output_prefix_data = &prefix;
+	diff_setup_done(&opts);
+
+	diff_tree_oid(oid1, oid2, "", &opts);
+	diffcore_std(&opts);
+	diff_flush(&opts);
+
+	strbuf_release(&prefix);
+}

diff.h

@@ -600,6 +600,13 @@ int index_differs_from(struct repository *r, const char *def,
 		       const struct diff_flags *flags,
 		       int ita_invisible_in_index);
 
+/*
+ * Emit an interdiff of two object ID's to 'diff_options.file' optionally
+ * indented by 'indent' spaces.
+ */
+void show_interdiff(const struct object_id *, const struct object_id *,
+		    int indent, struct diff_options *);
+
 /*
  * Fill the contents of the filespec "df", respecting any textconv defined by
  * its userdiff driver.  The "driver" parameter must come from a

interdiff.c

@@ -15,7 +15,6 @@
 #include "sequencer.h"
 #include "line-log.h"
 #include "help.h"
-#include "interdiff.h"
 #include "range-diff.h"
 
 static struct decoration name_decoration = { "object names" };
@@ -800,7 +799,8 @@ void show_log(struct rev_info *opt)
 
 		next_commentary_block(opt, NULL);
 		fprintf_ln(opt->diffopt.file, "%s", opt->idiff_title);
-		show_interdiff(opt, 2);
+		show_interdiff(opt->idiff_oid1, opt->idiff_oid2, 2,
+			       &opt->diffopt);
 
 		memcpy(&diff_queued_diff, &dq, sizeof(diff_queued_diff));
 	}