GIT Exercises: what changed

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Old	New		Line
1	1		This page has some exercises so you can experience different solutions/outcomes for a given task.
2	2
3	3		By providing these (partly trivial) examples, the page ensures that you will not miss any of the scenarios while discovering the wonders of GIT.
4	4
5	5		## Preface
6	6
7	7		Some of the examples are about how to deal with your work when other people are pushed in between.
8	8
9	9		For this you need a 2nd clone. See setup.
10	10
11	11		## Setup
12	12
13	13		The following steps should be performed before going to any of the below items.
14	14
15	15		Initial setup and clone
16	16
17	17		[[SVN to GIT Cheatsheet\|SVN_to_GIT_Cheatsheet#Setup]]
18	18
19	19		Second clone
20	20
21	21		To simulate what someone else would have done while you where working. This can use the same user, the effect will be the same.
22	22
23	23		You can either "git clone" again, or just make a copy of the entire directory into which you have cloned.
24	24
25	25		You can then in that 2nd clone alter your username
26	26
27		-	~~` git config user.name martin_2`~~
	27	+	```text
	28	+	git config user.name martin_2
	29	+	```
28	30
29	31		### Each example setup
30	32
31	33		In your first git folders, create a new branch
32	34
33		-	~~` git switch -c martins-test-1`\~~
34		-	~~` git push --set-upstream origin martins-test-1 ## tell the server there is a new branch`~~
	35	+	```text
	36	+	git switch -c martins-test-1
	37	+	git push --set-upstream origin martins-test-1 ## tell the server there is a new branch
	38	+	```
35	39
36	40		In your 2nd git folder
37	41
38		-	~~` git remote update`\~~
39		-	~~` git switch martins-test-1`~~
	42	+	```text
	43	+	git remote update
	44	+	git switch martins-test-1
	45	+	```
40	46
41	47		Thus both your folders are at the same branch, and are up to date with the remote
42	48
43	49		> Note: In the example you work on "martins-test-1". But it is setup the same as your trunk branch would be. Therefore the same will apply when you work on trunk
44	50
45	51		## Pushing your commit, if someone else made changes
46	52
47	53		> Note: If you followed the configuration your "git pull" should be configured to default to either "--ff-ony" or "--rebase".\
48	54		> The arguments given in to "pull" in the examples, will override the defaults
49	55
50	56		### Rebase
51	57
52	58		**In Folder1**
53	59
54	60		**In Folder2 (other person)**
55	61
56	62		Setup new branches #Each example setup
57	63
58	64		\\| Edit the file lcl/forms.pp
59	65
60		-	~~` git commit -m 'test changes' lcl/forms.pp`~~
	66	+	```text
	67	+	git commit -m 'test changes' lcl/forms.pp
	68	+	```
61	69
62		-	~~` git log --oneline --graph --all -n 2`\~~
63		-	~~` * 3b007fdc38 (HEAD -> martins-test-1) test changes`\~~
64		-	~~` * c739dd68a7 (origin/master, origin/HEAD) Revert "Test a change in forms"`~~
	70	+	```text
	71	+	git log --oneline --graph --all -n 2
	72	+	* 3b007fdc38 (HEAD -> martins-test-1) test changes
	73	+	* c739dd68a7 (origin/master, origin/HEAD) Revert "Test a change in forms"
	74	+	```
65	75
66	76		Your commit, follows the previous commit
67	77
68	78		\\|
69	79
70	80		\\|
71	81
72	82		\\| Edit the file ide/main.pp
73	83
74		-	~~` git commit -m 'test other' ide/main.pp`\~~
75		-	~~` git push`~~
	84	+	```text
	85	+	git commit -m 'test other' ide/main.pp
	86	+	git push
	87	+	```
76	88
77	89		\\|
78	90
79		-	~~` git push`\~~
80		-	~~` ! [rejected] martins-test-1 -> martins-test-1 (fetch first)`\~~
81		-	~~` error: failed to push some refs to '`[`https://gitlab.com/freepascal.org/lazarus_testconversion.git`](https://gitlab.com/freepascal.org/lazarus_testconversion.git)`'`~~
	91	+	```text
	92	+	git push
	93	+	! [rejected] martins-test-1 -> martins-test-1 (fetch first)
	94	+	error: failed to push some refs to 'https://gitlab.com/freepascal.org/lazarus_testconversion.git'
	95	+	```
82	96
83	97		Instead of the normal pull, we do a fetch. This will not resolve the problem, but we can see what it looks like.
84	98
85		-	~~` git fetch`~~
	99	+	```text
	100	+	git fetch
	101	+	```
86	102
87		-	~~` git log --oneline --graph --all -n 3`\~~
88		-	~~` * 46a817b6b3 (origin/martins-test-1) test other`\~~
89		-	~~` \| * 3b007fdc38 (HEAD -> martins-test-1) test changes`\~~
90		-	~~` \|/`\~~
91		-	~~` \| * c739dd68a7 (origin/master, origin/HEAD) Revert "Test a change in forms"`~~
	103	+	```text
	104	+	git log --oneline --graph --all -n 3
	105	+	* 46a817b6b3 (origin/martins-test-1) test other
	106	+	\| * 3b007fdc38 (HEAD -> martins-test-1) test changes
	107	+	\|/
	108	+	\| * c739dd68a7 (origin/master, origin/HEAD) Revert "Test a change in forms"
	109	+	```
92	110
93	111		\\|
94	112
95	113		For the #Merge example stop here, and continue in the next section
96	114
97	115		\\| You can see your commit still follows the same commit as before.
98	116
99	117		But on the server (origin/martins-test-1) there is the other commit, and it too has the same parent. The history on the server is fixed. We do not allow for it to be changed. So that commit will keep its parent.
100	118
101	119		In order to get your commit to the server, your local commit must change it's parent to "test other" (this is called "rebase")
102	120
103		-	~~` git pull --rebase`\~~
104		-	~~` Successfully rebased and updated refs/heads/martins-test-1.`~~
	121	+	```text
	122	+	git pull --rebase
	123	+	Successfully rebased and updated refs/heads/martins-test-1.
	124	+	```
105	125
106		-	~~` git log --oneline --graph --all -n 3`\~~
107		-	~~` * 2cbe840e7e (HEAD -> martins-test-1) test changes`\~~
108		-	~~` * 46a817b6b3 (origin/martins-test-1) test changes`\~~
109		-	~~` * c739dd68a7 (origin/master, origin/HEAD) Revert "Test a change in forms"`~~
	126	+	```text
	127	+	git log --oneline --graph --all -n 3
	128	+	* 2cbe840e7e (HEAD -> martins-test-1) test changes
	129	+	* 46a817b6b3 (origin/martins-test-1) test changes
	130	+	* c739dd68a7 (origin/master, origin/HEAD) Revert "Test a change in forms"
	131	+	```
110	132
111	133		Now your commit is on top, and we have a flat line of commits (like svn)
112	134
113		-	~~` git push`~~
	135	+	```text
	136	+	git push
	137	+	```
114	138
115	139		\\|
116	140
117	141		### Merge
118	142
119	143		> Warning: This example is what we want to avoid. This creates a diverged history (sub-branches). The log is no longer linear.
120	144
121	145		**In Folder1**
122	146
123	147		**In Folder2 (other person)**
124	148
125	149		Setup new branches #Each example setup
126	150
127	151		Repeat the steps from #Rebase above until you have done "git fetch" and reached the note for the "merge example"
128	152
129	153		\\|
130	154
131	155		Now run
132	156
133		-	~~` git pull --no-ff --no-rebase`\~~
134		-	~~` Merge made by the 'recursive' strategy.`\~~
135		-	~~` ide/main.pp \| 3 ---`\~~
136		-	~~` 1 file changed, 3 deletions(-)`~~
	157	+	```text
	158	+	git pull --no-ff --no-rebase
	159	+	Merge made by the 'recursive' strategy.
	160	+	ide/main.pp \| 3 ---
	161	+	1 file changed, 3 deletions(-)
	162	+	```
137	163
138	164		The --no-ff --no-rebase overrides any configs you may have made, and gets you the default behaviour of merging. Git will open an editor for you, and ask for a commit message for the merge. The merge creates a new commit.
139	165
140		-	~~` git log --oneline --graph --all -n 4`\~~
141		-	` * 044d9288b7 (HEAD -> martins-test-2) Merge branch 'martins-test-2' of `[`https://gitlab.com/freepascal.org/lazarus_testconversion`](https://gitlab.com/freepascal.org/lazarus_testconversion)` into martins-test-2`\
142		-	~~` \|\`\~~
143		-	~~` \| * 379b633c88 (origin/martins-test-2) test other`\~~
144		-	~~` * \| cfa3def67c test changes`\~~
145		-	~~` \|/`\~~
146		-	~~` * 2cbe840e7e foo bar`~~
	166	+	```text
	167	+	git log --oneline --graph --all -n 4
	168	+	* 044d9288b7 (HEAD -> martins-test-2) Merge branch 'martins-test-2' of https://gitlab.com/freepascal.org/lazarus_testconversion into martins-test-2
	169	+	\|\
	170	+	\| * 379b633c88 (origin/martins-test-2) test other
	171	+	* \| cfa3def67c test changes
	172	+	\|/
	173	+	* 2cbe840e7e foo bar
	174	+	```
147	175
148	176		As you can see the two commits are in different sub-branches (they are actually side by side). And a new merge commit has been added.
149	177
150	178		You can push this.
151	179
152	180		But this creates a commit log, like you would never see in svn.
153	181
154	182		\\|
155	183
156	184		### Fast Forward
157	185
158	186		> Note: In this example you will not have made a commit. Only the other person will have made a commit
159	187
160	188		Fast-Forward (FF) can only happen if
161	189
162	190		- there are new commits from a someone else
163	191		- but you have not made a commit yourself
164	192
165	193		**In Folder1**
166	194
167	195		**In Folder2 (other person)**
168	196
169	197		Setup new branches #Each example setup
170	198
171	199		\\| Edit the file lcl/forms.pp Do not commit the changes.
172	200
173		-	~~` git status -uno`\~~
174		-	~~` On branch martins-test-1`\~~
175		-	~~` Your branch is up to date with 'origin/martins-test-1'.`\~~
176		-	~~` `\~~
177		-	~~` Changes not staged for commit:`\~~
178		-	~~` (use "git add <file>..." to update what will be committed)`\~~
179		-	~~` (use "git restore <file>..." to discard changes in working directory)`\~~
180		-	~~` modified: lcl/forms.pp`~~
	201	+	```text
	202	+	git status -uno
	203	+	On branch martins-test-1
	204	+	Your branch is up to date with 'origin/martins-test-1'.
	205	+
	206	+	Changes not staged for commit:
	207	+	(use "git add <file>..." to update what will be committed)
	208	+	(use "git restore <file>..." to discard changes in working directory)
	209	+	modified: lcl/forms.pp
	210	+	```
181	211
182	212		Your changes are relative to the last commit
183	213
184		-	~~` git log --oneline -n1`\~~
185		-	~~` c739dd68a7 (HEAD -> martins-test-1) Foo bar"`~~
	214	+	```text
	215	+	git log --oneline -n1
	216	+	c739dd68a7 (HEAD -> martins-test-1) Foo bar"
	217	+	```
186	218
187	219		\\|
188	220
189	221		\\|
190	222
191	223		\\| Edit the file ide/main.pp
192	224
193		-	~~` git commit -m 'test other' ide/main.pp`\~~
194		-	~~` git push`~~
	225	+	```text
	226	+	git commit -m 'test other' ide/main.pp
	227	+	git push
	228	+	```
195	229
196	230		\\| Fetch the data from the remote
197	231
198		-	~~` git fetch`~~
	232	+	```text
	233	+	git fetch
	234	+	```
199	235
200	236		Status will tell you you are behind the remote
201	237
202		-	~~` git status -uno`\~~
203		-	~~` On branch martins-test-1`\~~
204		-	~~` Your branch is behind 'origin/martins-test-1' by 1 commit, and can be fast-forwarded.`\~~
205		-	~~` (use "git pull" to update your local branch)`\~~
206		-	~~` `\~~
207		-	~~` Changes not staged for commit:`\~~
208		-	~~` (use "git add <file>..." to update what will be committed)`\~~
209		-	~~` (use "git restore <file>..." to discard changes in working directory)`\~~
210		-	~~` modified: lcl/forms.pp`~~
	238	+	```text
	239	+	git status -uno
	240	+	On branch martins-test-1
	241	+	Your branch is behind 'origin/martins-test-1' by 1 commit, and can be fast-forwarded.
	242	+	(use "git pull" to update your local branch)
	243	+
	244	+	Changes not staged for commit:
	245	+	(use "git add <file>..." to update what will be committed)
	246	+	(use "git restore <file>..." to discard changes in working directory)
	247	+	modified: lcl/forms.pp
	248	+	```
211	249
212	250		Your changes are still relative to the last local commit. Indicated by "HEAD"
213	251
214		-	~~` git log --oneline -n2 origin/martins-test-1`\~~
215		-	~~` bc20668e78 (origin/martins-test-1) test other`\~~
216		-	~~` c739dd68a7 (HEAD -> martins-test-1) Foo bar"`~~
	252	+	```text
	253	+	git log --oneline -n2 origin/martins-test-1
	254	+	bc20668e78 (origin/martins-test-1) test other
	255	+	c739dd68a7 (HEAD -> martins-test-1) Foo bar"
	256	+	```
217	257
218		-	~~` git pull --ff-only`\~~
219		-	~~` Updating c739dd68a7..bc20668e78`\~~
220		-	~~` Fast-forward`\~~
221		-	~~` ide/main.pp \| 2 ++`\~~
222		-	~~` 1 file changed, 2 insertions(+)`~~
	258	+	```text
	259	+	git pull --ff-only
	260	+	Updating c739dd68a7..bc20668e78
	261	+	Fast-forward
	262	+	ide/main.pp \| 2 ++
	263	+	1 file changed, 2 insertions(+)
	264	+	```
223	265
224	266		Now the local branch "martins-test-1" has caught up to the remote branch. It includes the new commits. And it switched to the top commit.\
225	267		This catching up, is a fast forward.
226	268
227	269		- No local branches commits where changed/moved/added. Only the branch pointer moved
228	270		- Your changes are still there, and are now relative to the top commit
229	271
230		-	~~` git log --oneline -n2 --graph origin/martins-test-1`\~~
231		-	~~` bc20668e78 (HEAD -> martins-test-1, origin/martins-test-1) test other`\~~
232		-	~~` c739dd68a7 Foo bar"`~~
	272	+	```text
	273	+	git log --oneline -n2 --graph origin/martins-test-1
	274	+	bc20668e78 (HEAD -> martins-test-1, origin/martins-test-1) test other
	275	+	c739dd68a7 Foo bar"
	276	+	```
233	277
234	278		\\|
235	279
236	280		## Conflict Resolution
237	281
238	282		### Getting selected upstream changes
239	283
240	284		**In Folder1**
241	285
242	286		**In Folder2 (other person)**
243	287
244	288		Setup new branches #Each example setup
245	289
246	290		\\| Edit the file lcl/forms.pp\
247	291		Edit the file ide/main.pp somewhere from line 100 down
248	292
249		-	~~` git diff --stat`\~~
250		-	~~` ide/main.pp \| 5 +++++`\~~
251		-	~~` lcl/forms.pp \| 4 ++++`\~~
252		-	~~` 2 files changed, 9 insertions(+)`~~
	293	+	```text
	294	+	git diff --stat
	295	+	ide/main.pp \| 5 +++++
	296	+	lcl/forms.pp \| 4 ++++
	297	+	2 files changed, 9 insertions(+)
	298	+	```
253	299
254		-	~~` git log --oneline -n 1`\~~
255		-	~~` c739dd68a7 (HEAD -> martins-test-1) Foo Bar"`~~
	300	+	```text
	301	+	git log --oneline -n 1
	302	+	c739dd68a7 (HEAD -> martins-test-1) Foo Bar"
	303	+	```
256	304
257	305		\\|
258	306
259	307		\\|
260	308
261	309		\\| Edit the file ide/main.pp somewere in the first 20 lines (no conflict with the main user in folder1)\
262	310		Also edit the file lcl/grids.pas
263	311
264		-	~~` git commit -m 'test other' -a`\~~
265		-	~~` git push`~~
	312	+	```text
	313	+	git commit -m 'test other' -a
	314	+	git push
	315	+	```
266	316
267	317		\\| Update from remote. Keep current commit as base for your changes
268	318
269		-	~~` git fetch`\~~
270		-	~~` git log --oneline -n2 origin/martins-test-1`\~~
271		-	~~` 810b4f1bd4 (origin/martins-test-1) test other`\~~
272		-	~~` c739dd68a7 (HEAD -> martins-test-1) Foo Bar`~~
	319	+	```text
	320	+	git fetch
	321	+	git log --oneline -n2 origin/martins-test-1
	322	+	810b4f1bd4 (origin/martins-test-1) test other
	323	+	c739dd68a7 (HEAD -> martins-test-1) Foo Bar
	324	+	```
273	325
274	326		The commit "test other" changes several files. For testing you want to integrate the changes in file ide/main.pp, but no other changes.
275	327
276		-	~~` git stash`\~~
277		-	~~` git restore --source=origin/martins-test-1 ide/main.pp`\~~
278		-	~~` git commit -m 'dummy commit' ide/main.pp`\~~
279		-	~~` git stash pop`~~
	328	+	```text
	329	+	git stash
	330	+	git restore --source=origin/martins-test-1 ide/main.pp
	331	+	git commit -m 'dummy commit' ide/main.pp
	332	+	git stash pop
	333	+	```
280	334
281	335		Now you have a dummy commit with the changes to test. And your changes applied on top.
282	336
283		-	~~` git log --oneline -n2`\~~
284		-	~~` 63e2dcec9f (HEAD -> martins-test-1) dummy commit`\~~
285		-	~~` c739dd68a7 Foo Bar`\~~
286		-	~~` git diff --stat`\~~
287		-	~~` ide/main.pp \| 5 +++++`\~~
288		-	~~` lcl/forms.pp \| 4 ++++`\~~
289		-	~~` 2 files changed, 9 insertions(+)`~~
	337	+	```text
	338	+	git log --oneline -n2
	339	+	63e2dcec9f (HEAD -> martins-test-1) dummy commit
	340	+	c739dd68a7 Foo Bar
	341	+	git diff --stat
	342	+	ide/main.pp \| 5 +++++
	343	+	lcl/forms.pp \| 4 ++++
	344	+	2 files changed, 9 insertions(+)
	345	+	```
290	346
291	347		Now work with those changes, make further changes, eventually commit
292	348
293		-	~~` git commit -m 'my changes' -a`\~~
294		-	~~` [martins-test-1 9aba7218d1] my changes`\~~
295		-	~~` 2 files changed, 9 insertions(+)`~~
	349	+	```text
	350	+	git commit -m 'my changes' -a
	351	+	[martins-test-1 9aba7218d1] my changes
	352	+	2 files changed, 9 insertions(+)
	353	+	```
296	354
297		-	~~` git log --oneline -n5 --graph --all`\~~
298		-	~~` * 9aba7218d1 (HEAD -> martins-test-1) my changes`\~~
299		-	~~` * 63e2dcec9f dummy commit`\~~
300		-	~~` \| * 810b4f1bd4 (origin/martins-test-1) test other`\~~
301		-	~~` \|/`\~~
302		-	~~` * c739dd68a7 Foo Bar`~~
	355	+	```text
	356	+	git log --oneline -n5 --graph --all
	357	+	* 9aba7218d1 (HEAD -> martins-test-1) my changes
	358	+	* 63e2dcec9f dummy commit
	359	+	\| * 810b4f1bd4 (origin/martins-test-1) test other
	360	+	\|/
	361	+	* c739dd68a7 Foo Bar
	362	+	```
303	363
304	364		So you now need to rebase your changes on the origin/martins-test-1 to commit them.
305	365
306		-	~~` git pull --rebase`\~~
307		-	~~` Successfully rebased and updated refs/heads/martins-test-1.`~~
	366	+	```text
	367	+	git pull --rebase
	368	+	Successfully rebased and updated refs/heads/martins-test-1.
	369	+	```
308	370
309		-	~~` git log --oneline -n3`\~~
310		-	~~` f0d6afd90d (HEAD -> martins-test-1) my changes`\~~
311		-	~~` 810b4f1bd4 (origin/martins-test-1) test other`\~~
312		-	~~` c739dd68a7 Foo Bar`~~
	371	+	```text
	372	+	git log --oneline -n3
	373	+	f0d6afd90d (HEAD -> martins-test-1) my changes
	374	+	810b4f1bd4 (origin/martins-test-1) test other
	375	+	c739dd68a7 Foo Bar
	376	+	```
313	377
314	378		The "dummy commit" is gone. Because it was identical to existing changes. Of course you should check this. If it is still there you need to drop it with
315	379
316		-	~~` git rebase -i `~~
	380	+	```text
	381	+	git rebase -i
	382	+	```
317	383
318	384		\\|
319	385
320	386		---
321	387		From the Free Pascal wiki, page "GIT Exercises", as it stood on 2021-12-29 after a change by Trev, out of the wiki's dump of 2024-05-26. Copyright stays with the author who wrote it, according to the old wiki's [[Licensing]] page. If you have concerns about this material, [message the admin](/wiki-contact).
322	388		Category: Version Control

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