Creating A Patch: what changed

Revision 1 to 2. Removed lines have a minus sign; added lines have a plus sign.

Old	New		Line
1	1		If you want to submit improvements to the FPC or Lazarus code, you need to submit a patch which developers can easily merge.
2	2
3	3		Exceptions:
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5	5		1. .po translation files should be sent as whole files
6	6		2. new files should be sent as whole files, with instructions where they should be placed
7	7
8	8		## Requirements
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10	10		You need the main/development version of Lazarus (or FPC). You can get Lazarus using either Git or SVN.
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12	12		- Git: [[Getting Lazarus\|Getting Lazarus development version]]. This is the native repository.
13	13		- SVN: Read-only mirror of the official GitLab repository requires some svn gymnastics due to a bug in many versions of svn:
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15	15		`svn checkout --depth files `[`https://github.com/fpc/Lazarus/branches`](https://github.com/fpc/Lazarus/branches)` all`\
16	16		`cd all`\
17	17		`svn update --set-depth infinity main`
18	18
19	19		`svn checkout --depth files `[`https://github.com/fpc/FPCSource/branches`](https://github.com/fpc/FPCSource/branches)` all`\
20	20		`cd all`\
21	21		`svn update --set-depth infinity main`
22	22
23		-	> Warning: If you submit patches, do <u>not</u> base them on stable versions of Lazarus/FPC. Typically the development version is very different from stable versions as many improvements and fixes have been applied by the developers
	23	+	> Warning: If you submit patches, do not base them on stable versions of Lazarus/FPC. Typically the development version is very different from stable versions as many improvements and fixes have been applied by the developers
24	24
25	25		## Platform differences
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27	27		The instructions later assume you have opened a command prompt and moved (cd) to the directory of the repository. Here are the details :
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29	29		### Windows
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31	31		Assuming you checked out Lazarus into C:\lazarus, open command prompt (cmd.exe) and type "cd \lazarus".
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33	33		### *nix systems
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35	35		Assuming you checked out Lazarus into ~/lazarus, open terminal and type "cd ~/lazarus".
36	36
37	37		## Creating a patch using SVN
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39	39		``` bash
40	40		svn diff > mypatch.diff
41	41		```
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43	43		This includes all changed files in the whole SVN repository.
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45	45		You can also define the individual files, to make sure no garbage is included, eg. :
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47	47		``` bash
48	48		svn diff ide/main.pp ideintf/objectinspector.pp > mypatch.diff
49	49		```
50	50
51	51		> Note: If using [TortoiseSVN](http://tortoisesvn.tigris.org/) on Windows, you can select the folder where Lazarus was checked out in Windows Explorer then right click to select TortoiseSVN-\>Create Patch...
52	52
53	53		See also [[TortoiseSvn\|TortoiseSvn#Troubleshooting]] if you have problems.
54	54
55	55		## Creating a patch using Git
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57	57		First, develop your code in a separate branch! While your development branch is active, you can create patches of all your local commits by :
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59	59		``` bash
60	60		git format-patch master
61	61		```
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63	63		It creates a set of patches named like "0001-CommitMsg.patch", "0002-CommitMsg.patch" and so on.
64	64
65	65		If you want all the changes in one patch, either combine the commits using "git rebase -i ..." or use the following command :
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67	67		``` bash
68	68		git format-patch master --stdout > mypatch.patch
69	69		```
70	70
71	71		## Submitting the patch
72	72
73	73		Now you have a patch. I'd suggest to look the file over to see if it looks ok (no unexpected changes).
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75	75		The recommended way to submit a patch is through the [bug tracker](http://bugs.freepascal.org), see [[How do I create a bug report]] for details. If there is a report for the issue your patch fixes, use that, otherwise create a new issue. Upload the file to attach it to the issue.
76	76
77	77		## Git
78	78
79	79		The GitHub repository [1](https://github.com/graemeg/lazarus) is only a mirror and does not accept pull-requests.
80	80
81	81		## Applying a patch
82	82
83	83		This explains how to apply somebody else's patch to your local repository. You can test the patch by using the --dry-run toggle switch like this:
84	84
85	85		``` bash
86	86		patch --dry-run < somepatch.diff
87	87		```
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89	89		The output of the patch program will be identical to the actual patching, only it does not alter the sourcecode files. Very handy for testing, without the possibility to screw up your source.
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91	91		### A patch made with "svn diff"
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93	93		To do the final patching, use the following commandline:
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95	95		``` bash
96	96		patch < somepatch.diff
97	97		```
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99	99		If that doesn't work because the path layout of your environment is different from the environment where the patch was created, you can tell patch to strip out all path information:
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101	101		``` bash
102	102		patch -p0 < somepatch.diff
103	103		```
104	104
105	105		Any GUI tool for diffs on Windows can handle these patches, too, including TortoiseMerge.
106	106
107	107		### A patch made with "git format-patch"
108	108
109	109		#### Git
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111	111		Git itself applies the patch like this :
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113	113		``` bash
114	114		git apply 0001-gitpatch.patch
115	115		```
116	116
117	117		#### patch
118	118
119	119		The "patch" command now supports git format patches with -p1. This is tested with patch v.2.6.1 on Linux, old versions may not support it.
120	120
121	121		``` bash
122	122		patch -p1 < 0001-gitpatch.patch
123	123		```
124	124
125	125		"patch" is available for Windows, too, but there are also GUI tools for the job.
126	126
127	127		#### TortoiseMerge
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129	129		TortoiseMerge supports the Git format patch without problems. It is installed together with Tortoise SVN but is not integrated in explorer. It must be opened from the Start menu.
130	130
131	131		ToDo: add more GUI tools that support Git format patches
132	132
133	133		### Troubleshooting
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135	135		Finally, patches may have a Unix/Linux line ending (LF) while your local file has Windows (CR+LF) line endings or vice versa. You'll have to convert the patch file before applying on Windows at least, as the supplied patch.exe is picky about line endings.
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137	137		On Windows, the patch.exe supplied with FPC/Lazarus is very picky; you may have better luck with the patch.exe supplied by Git:
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139	139		```dos
140	140		"C:\Program Files (x86)\Git\bin\patch.exe" -p0 < mypatch.diff
141	141		```
142	142
143	143		... or the svn patch command available since SVN 1.7.
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145	145		## See also
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147	147		- [[How do I create a bug report]] general information on submitting bugs, what should be covered in a bug report, and using the bug tracker.
148	148		- [[Tips on writing bug reports]] detailed information on what should be covered in a bug report.
149	149		- [[Database bug reporting]] Specific info and sample programs for database bugs
150	150		- [[Moderating the bug tracker]]
151	151
152	152		---
153	153		From the Free Pascal wiki, page "Creating A Patch", as it stood on 2022-01-13 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).

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