git 回购中缺少行

Question

我的 git 存储库发生了一些奇怪的事情。
正如您从以下差异中看到的那样，首先我们添加了 console.log(config)，在下一次提交中我们删除了它，在最后一次我们再次删除了它，因为该行仍然存在于 repo 中。

这怎么可能？也许合并发生了一些奇怪的事情？

commit e28e546f003f4b55cc508e60b8a2c7ba3ad1ffab
Date:   Thu Jan 21 14:46:50 2021 +0100

    remove console log

diff --git a/lib/config.js b/lib/config.js
index 6f20b32..ba26ac3 100644
--- a/lib/config.js
+++ b/lib/config.js
@@ -293,8 +293,6 @@ for (let c in config) {
 
 config.i18n.supportedLocales = (config.i18n.locales).filter(l => l.iso === locale)
 
-console.log(config)
-
 const exportedConfig = {
   config: config,
   server: {

commit fc05a16cda8cd9f72d73b995af001dd4ef932a70
Merge: 5b1ef6e 86e1a6a
Date:   Wed Jan 20 17:53:14 2021 +0000

    Merge branch 'development' into 'staging'
    
    Development --> Staging
    
    See merge request !681

commit 86e1a6aaec44c65e89e0507caf463876d9323d86
Date:   Wed Jan 20 18:50:03 2021 +0100

    Fool GIT

diff --git a/lib/config.js b/lib/config.js
index 29d0c26..ba26ac3 100644
--- a/lib/config.js
+++ b/lib/config.js
@@ -289,6 +289,8 @@ for (let c in config) {
   }
 }
 
+/// console.log(config)
+
 config.i18n.supportedLocales = (config.i18n.locales).filter(l => l.iso === locale)
 
 const exportedConfig = {

commit fc85ca3069f9d76072a0488cade1477e47844e8d
Date:   Wed Jan 20 18:45:17 2021 +0100

    Remove console.log()

diff --git a/lib/config.js b/lib/config.js
index f2f295c..29d0c26 100644
--- a/lib/config.js
+++ b/lib/config.js
@@ -291,8 +291,6 @@ for (let c in config) {
 
 config.i18n.supportedLocales = (config.i18n.locales).filter(l => l.iso === locale)
 
-console.log(config)
-
 const exportedConfig = {
   config: config,
   server: {

commit f2d09dc045dd3e536a09929403e067c5c8fb8b62
Date:   Wed Jan 20 18:43:39 2021 +0100

    Restore console.log()

diff --git a/lib/config.js b/lib/config.js
index 29d0c26..f2f295c 100644
--- a/lib/config.js
+++ b/lib/config.js
@@ -291,6 +291,8 @@ for (let c in config) {
 
 config.i18n.supportedLocales = (config.i18n.locales).filter(l => l.iso === locale)
 
+console.log(config)
+
 const exportedConfig = {
   config: config,
   server: {

Answer 1

该行已添加到合并提交中。如果你 checkout 提交并打开 lib/config.js 你会在那里看到这些行。

那么，为什么这些行不显示在 diff 中？这很混乱，我会同意你的。这是因为 diff 不显示合并提交的差异。

每当它进行差异化时 git 需要知道哪些提交正在差异化。大多数提交都有一个父项，因此差异存在于每个提交与其父项之间。但是，合并提交有多个父项。它应该与哪个不同？有多个选项可供选择 git 并不知道如何显示有用的差异，所以它只显示提交消息。

有关更深入的解释，请参阅 this excellent answer:

Commits are not diffs; commits are snapshots. This might seem like a distinction without a difference—and for some commits, it is. But for merge commits, it's not.

When git show (or git log -p) shows a commit as a diff, it's doing so by comparing the commit's snapshot to something else. The git diff command does the same thing: it compares one commit to another commit. (Or it can compare a commit to the work-tree, or to the contents of the index, or a few other combinations as well.)

For ordinary commits, it's trivially obvious what to compare: compare this commit's snapshot to the previous (i.e., parent) commit's snapshot. So that is what git show does (and git log -p too): it runs a git diff from the parent commit, to this commit.

Merge commits don't have just one parent commit, though. They have two parents.¹ This is what makes them "merge commits" in the first place: the definition of a merge commit is a commit with at least two parents.

git 回购中缺少行

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