patch: handle files with no final newline

The 'patch' applet was unable to process diffs which included the
'\ No newline at end of file' warning.

Detect this case and mark the lines affected so they can be
emitted without a newline.

Adds 45-69 bytes.

(GitHub issue #575)

1 files changed, 18 insertions, 0 deletions

diff --git a/editors/patch.c b/editors/patch.c
index 5a768b23f..9f0689ec7 100644
--- a/editors/patch.c
+++ b/editors/patch.c
@@ -57,6 +57,9 @@ struct double_list {
         struct double_list *next;
         struct double_list *prev;
         char *data;
+#if ENABLE_PLATFORM_MINGW32
+        int no_newline;
+#endif
 };
 
 // Free all the elements of a linked list
@@ -76,7 +79,11 @@ static void dlist_free(struct double_list *list, void (*freeit)(void *data))
 static struct double_list *dlist_add(struct double_list **list, char *data)
 {
         struct double_list *llist;
+#if ENABLE_PLATFORM_MINGW32
+        struct double_list *line = xzalloc(sizeof(*line));
+#else
         struct double_list *line = xmalloc(sizeof(*line));
+#endif
 
         line->data = data;
         llist = *list;
@@ -140,6 +147,9 @@ static void do_line(void *data)
 
         if (TT.state > 1 && *dlist->data != TT.state)
                 fdprintf(TT.state == 2 ? 2 : TT.fileout,
+#if ENABLE_PLATFORM_MINGW32
+                        dlist->no_newline && TT.state != 2 ? "%s" :
+#endif
                         "%s\n", dlist->data + (TT.state > 3 ? 1 : 0));
 
         if (PATCH_DEBUG) fdprintf(2, "DO %d: %s\n", TT.state, dlist->data);
@@ -448,6 +458,14 @@ int patch_main(int argc UNUSED_PARAM, char **argv)
                                 if (!oldlen && !newlen) state = apply_one_hunk();
                                 continue;
                         }
+#if ENABLE_PLATFORM_MINGW32
+                        else if (*patchline == '\\' && TT.current_hunk->prev) {
+                                // detect '\ No newline at end of file' and mark previous
+                                // line, if it exists.
+                                TT.current_hunk->prev->no_newline = TRUE;
+                                continue;
+                        }
+#endif
                         fail_hunk();
                         state = 0;
                         continue;