Fix "git diff --stat" for interesting - but empty - file changes

The behavior of "git diff --stat" is rather odd for files that have
zero lines of changes: it will discount them entirely unless they were
renames.

Which means that the stat output will simply not show files that only
had "other" changes: they were created or deleted, or their mode was
changed.

Now, those changes do show up in the summary, but so do renames, so
the diffstat logic is inconsistent. Why does it show renames with zero
lines changed, but not mode changes or added files with zero lines
changed?

So change the logic to not check for "is_renamed", but for
"is_interesting" instead, where "interesting" is judged to be any
action but a pure data change (because a pure data change with zero
data changed really isn't worth showing, if we ever get one in our
diffpairs).

So if you did

   chmod +x Makefile
   git diff --stat

before, it would show empty (" 0 files changed"), with this it shows

 Makefile | 0
 1 file changed, 0 insertions(+), 0 deletions(-)

which I think is a more correct diffstat (and then with "--summary" it
shows *what* the metadata change to Makefile was - this is completely
consistent with our handling of renamed files).

Side note: the old behavior was *really* odd. With no changes at all,
"git diff --stat" output was empty. With just a chmod, it said "0
files changed". No way is our legacy behavior sane.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
4 files changed
tree: 766143938969c67fdb19c3da5782bd3020fd9fb3
  1. block-sha1/
  2. builtin/
  3. compat/
  4. contrib/
  5. Documentation/
  6. git-gui/
  7. git_remote_helpers/
  8. gitk-git/
  9. gitweb/
  10. mergetools/
  11. perl/
  12. po/
  13. ppc/
  14. t/
  15. templates/
  16. vcs-svn/
  17. xdiff/
  18. .gitattributes
  19. .gitignore
  20. .mailmap
  21. abspath.c
  22. aclocal.m4
  23. advice.c
  24. advice.h
  25. alias.c
  26. alloc.c
  27. archive-tar.c
  28. archive-zip.c
  29. archive.c
  30. archive.h
  31. argv-array.c
  32. argv-array.h
  33. attr.c
  34. attr.h
  35. base85.c
  36. bisect.c
  37. bisect.h
  38. blob.c
  39. blob.h
  40. branch.c
  41. branch.h
  42. builtin.h
  43. bulk-checkin.c
  44. bulk-checkin.h
  45. bundle.c
  46. bundle.h
  47. cache-tree.c
  48. cache-tree.h
  49. cache.h
  50. check-builtins.sh
  51. check-racy.c
  52. check_bindir
  53. color.c
  54. color.h
  55. column.c
  56. column.h
  57. combine-diff.c
  58. command-list.txt
  59. commit.c
  60. commit.h
  61. config.c
  62. config.mak.in
  63. configure.ac
  64. connect.c
  65. connected.c
  66. connected.h
  67. convert.c
  68. convert.h
  69. copy.c
  70. COPYING
  71. credential-cache--daemon.c
  72. credential-cache.c
  73. credential-store.c
  74. credential.c
  75. credential.h
  76. csum-file.c
  77. csum-file.h
  78. ctype.c
  79. daemon.c
  80. date.c
  81. decorate.c
  82. decorate.h
  83. delta.h
  84. diff-delta.c
  85. diff-lib.c
  86. diff-no-index.c
  87. diff.c
  88. diff.h
  89. diffcore-break.c
  90. diffcore-delta.c
  91. diffcore-order.c
  92. diffcore-pickaxe.c
  93. diffcore-rename.c
  94. diffcore.h
  95. dir.c
  96. dir.h
  97. editor.c
  98. entry.c
  99. environment.c
  100. exec_cmd.c
  101. exec_cmd.h
  102. fast-import.c
  103. fetch-pack.h
  104. fixup-builtins
  105. fmt-merge-msg.h
  106. fsck.c
  107. fsck.h
  108. generate-cmdlist.sh
  109. gettext.c
  110. gettext.h
  111. git-add--interactive.perl
  112. git-am.sh
  113. git-archimport.perl
  114. git-bisect.sh
  115. git-compat-util.h
  116. git-cvsexportcommit.perl
  117. git-cvsimport.perl
  118. git-cvsserver.perl
  119. git-difftool--helper.sh
  120. git-difftool.perl
  121. git-filter-branch.sh
  122. git-instaweb.sh
  123. git-lost-found.sh
  124. git-merge-octopus.sh
  125. git-merge-one-file.sh
  126. git-merge-resolve.sh
  127. git-mergetool--lib.sh
  128. git-mergetool.sh
  129. git-p4.py
  130. git-parse-remote.sh
  131. git-pull.sh
  132. git-quiltimport.sh
  133. git-rebase--am.sh
  134. git-rebase--interactive.sh
  135. git-rebase--merge.sh
  136. git-rebase.sh
  137. git-relink.perl
  138. git-remote-testgit.py
  139. git-repack.sh
  140. git-request-pull.sh
  141. git-send-email.perl
  142. git-sh-i18n.sh
  143. git-sh-setup.sh
  144. git-stash.sh
  145. git-submodule.sh
  146. git-svn.perl
  147. GIT-VERSION-GEN
  148. git-web--browse.sh
  149. git.c
  150. git.spec.in
  151. gpg-interface.c
  152. gpg-interface.h
  153. graph.c
  154. graph.h
  155. grep.c
  156. grep.h
  157. hash.c
  158. hash.h
  159. help.c
  160. help.h
  161. hex.c
  162. http-backend.c
  163. http-fetch.c
  164. http-push.c
  165. http-walker.c
  166. http.c
  167. http.h
  168. ident.c
  169. imap-send.c
  170. INSTALL
  171. kwset.c
  172. kwset.h
  173. levenshtein.c
  174. levenshtein.h
  175. LGPL-2.1
  176. list-objects.c
  177. list-objects.h
  178. ll-merge.c
  179. ll-merge.h
  180. lockfile.c
  181. log-tree.c
  182. log-tree.h
  183. mailmap.c
  184. mailmap.h
  185. Makefile
  186. match-trees.c
  187. merge-file.c
  188. merge-file.h
  189. merge-recursive.c
  190. merge-recursive.h
  191. mergesort.c
  192. mergesort.h
  193. name-hash.c
  194. notes-cache.c
  195. notes-cache.h
  196. notes-merge.c
  197. notes-merge.h
  198. notes.c
  199. notes.h
  200. object.c
  201. object.h
  202. pack-check.c
  203. pack-refs.c
  204. pack-refs.h
  205. pack-revindex.c
  206. pack-revindex.h
  207. pack-write.c
  208. pack.h
  209. pager.c
  210. parse-options-cb.c
  211. parse-options.c
  212. parse-options.h
  213. patch-delta.c
  214. patch-ids.c
  215. patch-ids.h
  216. path.c
  217. pkt-line.c
  218. pkt-line.h
  219. preload-index.c
  220. pretty.c
  221. progress.c
  222. progress.h
  223. prompt.c
  224. prompt.h
  225. quote.c
  226. quote.h
  227. reachable.c
  228. reachable.h
  229. read-cache.c
  230. README
  231. reflog-walk.c
  232. reflog-walk.h
  233. refs.c
  234. refs.h
  235. remote-curl.c
  236. remote.c
  237. remote.h
  238. replace_object.c
  239. rerere.c
  240. rerere.h
  241. resolve-undo.c
  242. resolve-undo.h
  243. revision.c
  244. revision.h
  245. run-command.c
  246. run-command.h
  247. send-pack.h
  248. sequencer.c
  249. sequencer.h
  250. server-info.c
  251. setup.c
  252. sh-i18n--envsubst.c
  253. sha1-array.c
  254. sha1-array.h
  255. sha1-lookup.c
  256. sha1-lookup.h
  257. sha1_file.c
  258. sha1_name.c
  259. shallow.c
  260. shell.c
  261. shortlog.h
  262. show-index.c
  263. sideband.c
  264. sideband.h
  265. sigchain.c
  266. sigchain.h
  267. strbuf.c
  268. strbuf.h
  269. streaming.c
  270. streaming.h
  271. string-list.c
  272. string-list.h
  273. submodule.c
  274. submodule.h
  275. symlinks.c
  276. tag.c
  277. tag.h
  278. tar.h
  279. test-chmtime.c
  280. test-ctype.c
  281. test-date.c
  282. test-delta.c
  283. test-dump-cache-tree.c
  284. test-genrandom.c
  285. test-index-version.c
  286. test-line-buffer.c
  287. test-match-trees.c
  288. test-mergesort.c
  289. test-mktemp.c
  290. test-parse-options.c
  291. test-path-utils.c
  292. test-regex.c
  293. test-revision-walking.c
  294. test-run-command.c
  295. test-scrap-cache-tree.c
  296. test-sha1.c
  297. test-sha1.sh
  298. test-sigchain.c
  299. test-string-list.c
  300. test-subprocess.c
  301. test-svn-fe.c
  302. thread-utils.c
  303. thread-utils.h
  304. trace.c
  305. transport-helper.c
  306. transport.c
  307. transport.h
  308. tree-diff.c
  309. tree-walk.c
  310. tree-walk.h
  311. tree.c
  312. tree.h
  313. unimplemented.sh
  314. unix-socket.c
  315. unix-socket.h
  316. unpack-trees.c
  317. unpack-trees.h
  318. upload-pack.c
  319. url.c
  320. url.h
  321. usage.c
  322. userdiff.c
  323. userdiff.h
  324. utf8.c
  325. utf8.h
  326. varint.c
  327. varint.h
  328. version.c
  329. version.h
  330. walker.c
  331. walker.h
  332. wrap-for-bin.sh
  333. wrapper.c
  334. write_or_die.c
  335. ws.c
  336. wt-status.c
  337. wt-status.h
  338. xdiff-interface.c
  339. xdiff-interface.h
  340. zlib.c