vim patches 7.4.955/974/975/989. #3919

Helped by @Shougo.

vim-patch:7.4.955
vim-patch:7.4.974
vim-patch:7.4.975
vim-patch:7.4.989

Port upstream vim patches 955, 974, 975 and 989. Mark patches
964, 968, 970, and 971, and 982 as NA. Update patch list to 1022.

patch 7.4.955
Problem:    Vim doesn't recognize .pl6 and .pod6 files.
Solution:   Recognize them as perl6 and pod6. (Mike Eve)

patch 7.4.974
Problem:    When using :diffsplit the cursor jumps to the first line.
Solution:   Put the cursor on the line related to where the cursor was before
            the split.

patch 7.4.975
Problem:    Using ":sort" on a very big file sometimes causes text to be
            corrupted. (John Beckett)
Solution:   Copy the line into a buffer before calling ml_append().

patch 7.4.989
Problem:    Leaking memory when hash_add() fails. Coverity error 99126.
Solution:   When hash_add() fails free the memory.

778 marked as not NA as it will be needed once vim patch 754 is merged

Marked as NA:
964 test 87 was deleted
968 tests 86/87 were deleted
970 guarded by: `# if defined(FEAT_GUI_GTK) || defined(PROTO`
    and is inside a function that no longer exists
971 function table already sorted correctly
982 marked as NA because Neovim tests are only specified in exactly one location

1 files changed, 4 insertions, 1 deletions

diff --git a/src/nvim/eval.c b/src/nvim/eval.c
index a1321d0227..7ac51d7bd7 100644
--- a/src/nvim/eval.c
+++ b/src/nvim/eval.c
@@ -19793,7 +19793,10 @@ void ex_function(exarg_T *eap)
 
     /* insert the new function in the function list */
     STRCPY(fp->uf_name, name);
-    hash_add(&func_hashtab, UF2HIKEY(fp));
+    if (hash_add(&func_hashtab, UF2HIKEY(fp)) == FAIL) {
+        xfree(fp);
+        goto erret;
+    }
   }
   fp->uf_refcount = 1;
   fp->uf_args = newargs;