patch 7.4.803
Problem:    C indent does not support C11 raw strings. (Mark Lodato)
Solution:   Do not change indent inside the raw string.
diff --git a/src/edit.c b/src/edit.c
index 5d3bd82..b48a217 100644
--- a/src/edit.c
+++ b/src/edit.c
@@ -7813,9 +7813,14 @@
 fixthisline(get_the_indent)
     int (*get_the_indent) __ARGS((void));
 {
-    change_indent(INDENT_SET, get_the_indent(), FALSE, 0, TRUE);
-    if (linewhite(curwin->w_cursor.lnum))
-	did_ai = TRUE;	    /* delete the indent if the line stays empty */
+    int amount = get_the_indent();
+
+    if (amount >= 0)
+    {
+	change_indent(INDENT_SET, amount, FALSE, 0, TRUE);
+	if (linewhite(curwin->w_cursor.lnum))
+	    did_ai = TRUE;	/* delete the indent if the line stays empty */
+    }
 }
 
     void