…fancyweb, javiereguiluz)

This PR was merged into the 2.7 branch.

Discussion
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Add a warning about routes parameters names limitations

@wouterj @xabbuh

I'm sorry guys I had to do a new branch and a new PR because I failed in the old one. I shouldn't have used the fast GitHub edit method.

I fixed the indentation to 4 spaces.

Also I thought this kind of information fitted more in the "advanced" area along with the special parameters than in the basic examples.

Follow up to #7133

Commits
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cadef60 Use "route placeholder" instead of "route parameter"
6b0f53c Add a warning about routes parameters names limitations

… be used as a PCRE subpattern name (fancyweb)

This PR was squashed before being merged into the 2.7 branch (closes #20474).

Discussion
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[Routing] Fail properly when a route parameter name cannot be used as a PCRE subpattern name

| Q             | A
| ------------- | ---
| Branch?       | 2.7
| Bug fix?      | no
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | -
| License       | MIT
| Doc PR        | symfony/symfony-docs#7139

This is a follow up PR to #20327.

I also decided to improve the current `is_numeric()` check that is done by a truer one. The current limitation is that a PCRE subpattern name must not start with a digit which is different.

Commits
-------

73fbd08 [Routing] Fail properly when a route parameter name cannot be used as a PCRE subpattern name

… be used as a PCRE subpattern name (fancyweb)

This PR was squashed before being merged into the 2.7 branch (closes #20474).

Discussion
----------

[Routing] Fail properly when a route parameter name cannot be used as a PCRE subpattern name

| Q             | A
| ------------- | ---
| Branch?       | 2.7
| Bug fix?      | no
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | -
| License       | MIT
| Doc PR        | symfony/symfony-docs#7139

This is a follow up PR to symfony/symfony#20327.

I also decided to improve the current `is_numeric()` check that is done by a truer one. The current limitation is that a PCRE subpattern name must not start with a digit which is different.

Commits
-------

73fbd08 [Routing] Fail properly when a route parameter name cannot be used as a PCRE subpattern name