BUG: fixed merging with empty frame containing an Int64 column (#25183)
State: closed

- [x] closes #25183
- [x] tests added / passed
- [x] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`
- [x] whatsnew entry


Labels:
name: Reshaping
description: Concat, Merge/Join, Stack/Unstack, Explode
name: Dtype Conversions
description: Unexpected or buggy dtype conversions
name: ExtensionArray
description: Extending pandas with custom dtypes or arrays.

Comments:
# [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/25289?src=pr&el=h1) Report
> Merging [#25289](https://codecov.io/gh/pandas-dev/pandas/pull/25289?src=pr&el=desc) into [master](https://codecov.io/gh/pandas-dev/pandas/commit/f74aba614554d1de4d7986fef6296a4eda951ac9?src=pr&el=desc) will **increase** coverage by `<.01%`.
> The diff coverage is `100%`.

[![Impacted file tree graph](https://codecov.io/gh/pandas-dev/pandas/pull/25289/graphs/tree.svg?width=650&token=eZ4WkYLtcO&height=150&src=pr)](https://codecov.io/gh/pandas-dev/pandas/pull/25289?src=pr&el=tree)

```diff
@@            Coverage Diff             @@
##           master   #25289      +/-   ##
==========================================
+ Coverage   91.73%   91.73%   +<.01%     
==========================================
  Files         173      173              
  Lines       52839    52843       +4     
==========================================
+ Hits        48472    48478       +6     
+ Misses       4367     4365       -2
```

| Flag | Coverage Δ | |
|---|---|---|
| #multiple | `90.3% <100%> (ø)` | :arrow_up: |
| #single | `41.75% <0%> (+0.03%)` | :arrow_up: |

| [Impacted Files](https://codecov.io/gh/pandas-dev/pandas/pull/25289?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [pandas/core/internals/concat.py](https://codecov.io/gh/pandas-dev/pandas/pull/25289/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvaW50ZXJuYWxzL2NvbmNhdC5weQ==) | `96.48% <100%> (+0.02%)` | :arrow_up: |
| [pandas/io/excel/\_util.py](https://codecov.io/gh/pandas-dev/pandas/pull/25289/diff?src=pr&el=tree#diff-cGFuZGFzL2lvL2V4Y2VsL191dGlsLnB5) | `78.82% <0%> (-1.83%)` | :arrow_down: |
| [pandas/core/arrays/timedeltas.py](https://codecov.io/gh/pandas-dev/pandas/pull/25289/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvYXJyYXlzL3RpbWVkZWx0YXMucHk=) | `88.2% <0%> (-0.11%)` | :arrow_down: |
| [pandas/io/excel/\_base.py](https://codecov.io/gh/pandas-dev/pandas/pull/25289/diff?src=pr&el=tree#diff-cGFuZGFzL2lvL2V4Y2VsL19iYXNlLnB5) | `92.48% <0%> (-0.04%)` | :arrow_down: |
| [pandas/core/generic.py](https://codecov.io/gh/pandas-dev/pandas/pull/25289/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvZ2VuZXJpYy5weQ==) | `94.16% <0%> (-0.01%)` | :arrow_down: |
| [pandas/core/arrays/datetimes.py](https://codecov.io/gh/pandas-dev/pandas/pull/25289/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvYXJyYXlzL2RhdGV0aW1lcy5weQ==) | `97.79% <0%> (ø)` | :arrow_up: |
| [pandas/core/frame.py](https://codecov.io/gh/pandas-dev/pandas/pull/25289/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvZnJhbWUucHk=) | `96.87% <0%> (ø)` | :arrow_up: |
| [pandas/core/indexes/base.py](https://codecov.io/gh/pandas-dev/pandas/pull/25289/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvaW5kZXhlcy9iYXNlLnB5) | `96.55% <0%> (ø)` | :arrow_up: |
| [pandas/core/indexing.py](https://codecov.io/gh/pandas-dev/pandas/pull/25289/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvaW5kZXhpbmcucHk=) | `92.29% <0%> (+0.02%)` | :arrow_up: |
| [pandas/util/testing.py](https://codecov.io/gh/pandas-dev/pandas/pull/25289/diff?src=pr&el=tree#diff-cGFuZGFzL3V0aWwvdGVzdGluZy5weQ==) | `87.66% <0%> (+0.09%)` | :arrow_up: |
| ... and [1 more](https://codecov.io/gh/pandas-dev/pandas/pull/25289/diff?src=pr&el=tree-more) | |

------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/25289?src=pr&el=continue).
> **Legend** - [Click here to learn more](https://docs.codecov.io/docs/codecov-delta)
> `Δ = absolute <relative> (impact)`, `ø = not affected`, `? = missing data`
> Powered by [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/25289?src=pr&el=footer). Last update [f74aba6...5d3e691](https://codecov.io/gh/pandas-dev/pandas/pull/25289?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).

Good start!  Looks like we have test failures though...
Hello @josham! Thanks for updating the PR.





Cheers ! There are no PEP8 issues in this Pull Request. :beers: 

##### Comment last updated on February 20, 2019 at 14:53 Hours UTC
I tested this to work around the described bug in my application and that fixed it.
thanks @josham nice patch! keep em coming
Something went wrong ... Please have  a look at my logs.