gin fix Request.Context() checks

Fixes nil pointer dereference panic introduced here: https://github.com/gin-gonic/gin/pull/3172 Closes https://github.com/gin-gonic/gin/issues/3343 Closes https://github.com/gin-gonic/gin/issues/3581 Closes https://github.com/gin-gonic/gin/issues/3483 Closes https://github.com/gin-gonic/gin/issues/3178

c.engine.ContextWithFallback check panics in Deadline(), Done(), Err() and Value() when c.engine is nil.

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Feb 25 '23 12:02 bvidosits

Codecov Report

Merging #3512 (81c6b90) into master (6a0556e) will decrease coverage by 0.38%. The diff coverage is 100.00%.

:exclamation: Current head 81c6b90 differs from pull request most recent head f6e9c8c. Consider uploading reports for the commit f6e9c8c to get more accurate results

@@            Coverage Diff             @@
##           master    #3512      +/-   ##
==========================================
- Coverage   99.01%   98.63%   -0.38%     
==========================================
  Files          42       42              
  Lines        3151     3155       +4     
==========================================
- Hits         3120     3112       -8     
- Misses         21       29       +8     
- Partials       10       14       +4

Flag	Coverage Δ
	`98.63% <100.00%> (-0.38%)`	:arrow_down:
go-1.18	`98.54% <100.00%> (-0.38%)`	:arrow_down:
go-1.19	`98.63% <100.00%> (-0.38%)`	:arrow_down:
go-1.20	`98.63% <100.00%> (-0.38%)`	:arrow_down:
macos-latest	`98.63% <100.00%> (-0.38%)`	:arrow_down:
ubuntu-latest	`98.63% <100.00%> (-0.38%)`	:arrow_down:

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
context.go	`97.98% <100.00%> (+0.01%)`	:arrow_up:

... and 1 file with indirect coverage changes

Feb 26 '23 11:02 codecov[bot]

Looks very good😁

Feb 27 '23 07:02 monkey92t

this bug was imported from #3172 before checking c.engine.ContextWithFallback, c.engine should be checked. also solved #3285

@thinkerou please merge this pr, for this bug has been imported for more than 2 versions. it cause inconsitant result:

<= 1.8.0 works fine
>= 1.8.1 sadly a panic

Mar 30 '23 10:03 Laotree

@javierprovecho @appleboy @thinkerou what needs to be done in order to merge this in? would like to be able to upgrade past gin 1.8.0 😅

for anyone that runs into this when creating an empty gin context, using gin.CreateTestContext will give you a context that doesn't panic upon attempting to retrieve a nonexistent context value.

i still think that this PR should be merged, as the current check is faulty and panics.