Merge branch 'maint-1.6.0' into maint-1.6.1

* maint-1.6.0:
diff -c -p: do not die on submodules

diff --cc combine-diff.c
index bccc018ab2666e769e7865d3cad1d61f04443700,f617e9ded6b7ff2bb7a8d3629480c2ad22667428..0b071b6e256fa655b51f9e484f0633a7f055dd25
--- 1/combine-diff.c
--- 2/combine-diff.c
+++ b/combine-diff.c
@@@ -211,12 -221,14 +219,12 @@@ static void combine_diff(const unsigne
        if (!cnt)
                return; /* result deleted */
  
-       parent_file.ptr = grab_blob(parent, &sz);
+       parent_file.ptr = grab_blob(parent, mode, &sz);
        parent_file.size = sz;
 +      memset(&xpp, 0, sizeof(xpp));
        xpp.flags = XDF_NEED_MINIMAL;
        memset(&xecfg, 0, sizeof(xecfg));
 -      ecb.outf = xdiff_outf;
 -      ecb.priv = &state;
        memset(&state, 0, sizeof(state));
 -      state.xm.consume = consume_line;
        state.nmask = nmask;
        state.sline = sline;
        state.lno = 1;
@@@ -688,12 -698,9 +696,12 @@@ static void show_patch_diff(struct comb
        mmfile_t result_file;
  
        context = opt->context;
 +      a_prefix = opt->a_prefix ? opt->a_prefix : "a/";
 +      b_prefix = opt->b_prefix ? opt->b_prefix : "b/";
 +
        /* Read the result of merge first */
        if (!working_tree_file)
-               result = grab_blob(elem->sha1, &result_size);
+               result = grab_blob(elem->sha1, elem->mode, &result_size);
        else {
                /* Used by diff-tree to read from the working tree */
                struct stat st;
@@@ -710,12 -718,15 +718,16 @@@
                                      strerror(errno));
                                return;
                        }
 -                      result[len] = 0;
 +                      result_size = buf.len;
 +                      result = strbuf_detach(&buf, NULL);
                        elem->mode = canon_mode(st.st_mode);
-               }
-               else if (0 <= (fd = open(elem->path, O_RDONLY)) &&
-                        !fstat(fd, &st)) {
+               } else if (S_ISDIR(st.st_mode)) {
+                       unsigned char sha1[20];
+                       if (resolve_gitlink_ref(elem->path, "HEAD", sha1) < 0)
+                               result = grab_blob(elem->sha1, elem->mode, &result_size);
+                       else
+                               result = grab_blob(sha1, elem->mode, &result_size);
+               } else if (0 <= (fd = open(elem->path, O_RDONLY))) {
                        size_t len = xsize_t(st.st_size);
                        ssize_t done;
                        int is_file, i;

diff --cc t/t4027-diff-submodule.sh
Simple merge