Merge branch 'jc/diffcore-rotate'

[thirdparty/git.git] / diffcore-rotate.c

diff --git a/diffcore-rotate.c b/diffcore-rotate.c
new file mode 100644 (file)
index 0000000..445f060
--- /dev/null
+++ b/diffcore-rotate.c
@@ -0,0 +1,46 @@
+/*
+ * Copyright (C) 2021, Google LLC.
+ * Based on diffcore-order.c, which is Copyright (C) 2005, Junio C Hamano
+ */
+#include "cache.h"
+#include "diff.h"
+#include "diffcore.h"
+
+void diffcore_rotate(struct diff_options *opt)
+{
+       struct diff_queue_struct *q = &diff_queued_diff;
+       struct diff_queue_struct outq;
+       int rotate_to, i;
+
+       if (!q->nr)
+               return;
+
+       for (i = 0; i < q->nr; i++) {
+               int cmp = strcmp(opt->rotate_to, q->queue[i]->two->path);
+               if (!cmp)
+                       break; /* exact match */
+               if (!opt->rotate_to_strict && cmp < 0)
+                       break; /* q->queue[i] is now past the target pathname */
+       }
+
+       if (q->nr <= i) {
+               /* we did not find the specified path */
+               if (opt->rotate_to_strict)
+                       die(_("No such path '%s' in the diff"), opt->rotate_to);
+               return;
+       }
+
+       DIFF_QUEUE_CLEAR(&outq);
+       rotate_to = i;
+
+       for (i = rotate_to; i < q->nr; i++)
+               diff_q(&outq, q->queue[i]);
+       for (i = 0; i < rotate_to; i++) {
+               if (opt->skip_instead_of_rotate)
+                       diff_free_filepair(q->queue[i]);
+               else
+                       diff_q(&outq, q->queue[i]);
+       }
+       free(q->queue);
+       *q = outq;
+}