First attempt on solving the issue

src/Paket.Core/Dependencies/PackageResolver.fs

@@ -44,10 +44,11 @@ type GetPackageDetailsParameters =
         GetPackageDetailsParameters.ofParamsEx false sources groupName packageName version
 
 type GetPackageVersionsParameters =
-  { Package : SourcePackageInfo }
-    static member ofParams sources groupName packageName =
+  { Package : SourcePackageInfo
+    MinVersion : SemVerInfo option }
+    static member ofParams sources groupName packageName minVersion =
         SourcePackageInfo.ofParams sources groupName packageName
-        |> fun p -> { Package = p }
+        |> fun p -> { Package = p; MinVersion = minVersion }
 
 type PackageDetailsFunc = GetPackageDetailsParameters -> Async<PackageDetails>
 type PackageDetailsSyncFunc = GetPackageDetailsParameters -> PackageDetails
@@ -585,7 +586,8 @@ let private getCompatibleVersions
             let resolverStrategy = getResolverStrategy globalStrategyForDirectDependencies globalStrategyForTransitives rootDependencies allRequirementsOfCurrentPackage currentRequirement
 
             let allVersions =
-                getVersionsF resolverStrategy (GetPackageVersionsParameters.ofParams currentRequirement.Sources groupName currentRequirement.Name)
+                let versionParams = GetPackageVersionsParameters.ofParams currentRequirement.Sources groupName currentRequirement.Name currentRequirement.MinVersionSetting
+                getVersionsF resolverStrategy versionParams
                 |> Seq.map (fun (v, sources) -> VersionCache.ofParams v sources false)
 
             match currentRequirement.VersionRequirement.Range with
@@ -1079,8 +1081,26 @@ let Resolve (getVersionsRaw : PackageVersionsFunc, getPreferredVersionsRaw : Pre
             let sorted =
                 match resolverStrategy with
                 | ResolverStrategy.Max -> List.sortDescending versions
-                | ResolverStrategy.LatestPatch -> List.sortDescending versions
-                | ResolverStrategy.LatestMinor -> List.sortDescending versions
+                | ResolverStrategy.LatestPatch ->
+                    match versionParams.MinVersion with 
+                    | Some minVersion -> 
+                        let preferred =
+                            versions
+                            |> List.filter (fun (v,s) -> v.Major = minVersion.Major && v.Minor = minVersion.Minor)
+                            |> List.sortDescending 
+
+                        preferred @ List.sortDescending versions
+                    | None -> List.sortDescending versions
+                | ResolverStrategy.LatestMinor ->
+                    match versionParams.MinVersion with 
+                    | Some minVersion -> 
+                        let preferred =
+                            versions
+                            |> List.filter (fun (v,s) -> v.Major = minVersion.Major)
+                            |> List.sortDescending 
+
+                        preferred @ List.sortDescending versions
+                    | None -> List.sortDescending versions
                 | ResolverStrategy.Min -> List.sort versions
 
             yield! sorted }
@@ -1176,7 +1196,8 @@ let Resolve (getVersionsRaw : PackageVersionsFunc, getPreferredVersionsRaw : Pre
 
                 let currentConflict =
                     let getVersionsF packName =
-                        getVersionsBlock ResolverStrategy.Max (GetPackageVersionsParameters.ofParams currentRequirement.Sources groupName packName) currentStep
+                        let versionParameters = GetPackageVersionsParameters.ofParams currentRequirement.Sources groupName packName currentRequirement.MinVersionSetting
+                        getVersionsBlock ResolverStrategy.Max versionParameters currentStep
 
                     if Seq.isEmpty conflicts then
                         { currentConflict with
@@ -1298,7 +1319,8 @@ let Resolve (getVersionsRaw : PackageVersionsFunc, getPreferredVersionsRaw : Pre
                     if not alreadyExplored then
                         for (pack,verReq,restr) in exploredPackage.Dependencies do
                             async {
-                                let requestVersions = startRequestGetVersions (GetPackageVersionsParameters.ofParams currentRequirement.Sources groupName pack)
+                                let versionParameters = GetPackageVersionsParameters.ofParams currentRequirement.Sources groupName pack currentRequirement.MinVersionSetting
+                                let requestVersions = startRequestGetVersions versionParameters
                                 requestVersions.Work.TryReprioritize true WorkPriority.LikelyRequired
                                 let! versions = (requestVersions).Work.Task |> Async.AwaitTask
                                 // Preload the first version in range of this requirement
@@ -1371,7 +1393,8 @@ let Resolve (getVersionsRaw : PackageVersionsFunc, getPreferredVersionsRaw : Pre
                             step (Step((currentConflict,nextStep,currentRequirement), (currentConflict,currentStep,currentRequirement,compatibleVersions,flags)::priorConflictSteps)) stackpack currentConflict.VersionsToExplore flags
                         else
                             let getVersionsF packName =
-                                getVersionsBlock ResolverStrategy.Max (GetPackageVersionsParameters.ofParams currentRequirement.Sources groupName packName) currentStep
+                                let versionParameters = GetPackageVersionsParameters.ofParams currentRequirement.Sources groupName packName currentRequirement.MinVersionSetting
+                                getVersionsBlock ResolverStrategy.Max versionParameters currentStep
 
                             let conflictingPackageName,vr =
                                 match Seq.tryHead conflictingResolvedPackages with
@@ -1401,13 +1424,17 @@ let Resolve (getVersionsRaw : PackageVersionsFunc, getPreferredVersionsRaw : Pre
     }
 
     for openReq in startingStep.OpenRequirements do
-        startRequestGetVersions (GetPackageVersionsParameters.ofParams openReq.Sources groupName openReq.Name)
+        let versionParamters = GetPackageVersionsParameters.ofParams openReq.Sources groupName openReq.Name openReq.MinVersionSetting
+        startRequestGetVersions versionParamters
         |> ignore
 
     let currentRequirement = getCurrentRequirement packageFilter startingStep.OpenRequirements (Dictionary())
 
     let status =
-        let getVersionsF packName = getVersionsBlock ResolverStrategy.Max (GetPackageVersionsParameters.ofParams currentRequirement.Sources groupName packName) startingStep
+        let getVersionsF packName = 
+            let versionParameters = GetPackageVersionsParameters.ofParams currentRequirement.Sources groupName packName currentRequirement.MinVersionSetting
+            getVersionsBlock ResolverStrategy.Max versionParameters startingStep
+
         ResolutionRaw.ConflictRaw { ResolveStep = startingStep; RequirementSet = Set.empty; Requirement = currentRequirement; GetPackageVersions = getVersionsF }
 
 

src/Paket.Core/PublicAPI.fs

@@ -720,7 +720,8 @@ type Dependencies(dependenciesFileName: string) =
             |> List.distinct
 
         let versions =
-            NuGet.GetVersions true alternativeProjectRoot root (GetPackageVersionsParameters.ofParams sources (GroupName "") (PackageName name))
+            let versionParameters = GetPackageVersionsParameters.ofParams sources (GroupName "") (PackageName name) None
+            NuGet.GetVersions true alternativeProjectRoot root versionParameters
             |> Async.RunSynchronously
             |> List.map (fun (v,_) -> v.ToString())
             |> List.toArray

src/Paket.Core/Versioning/Requirements.fs

@@ -1220,6 +1220,18 @@ type PackageRequirement =
 
     member this.Depth = this.Graph.Count
 
+    member this.MinVersionSetting =
+        match this.VersionRequirement with
+        | VersionRequirement(v,_) ->
+            match v with
+            | Minimum v -> Some v
+            | GreaterThan _ -> None
+            | Maximum _ -> None
+            | LessThan _ -> None
+            | Specific _ -> None
+            | OverrideAll _ -> None
+            | Range _ -> None
+
     member this.SettingString = (sprintf "%O %s %s %O %s" this.VersionRequirement (if this.ResolverStrategyForTransitives.IsSome then (sprintf "%O" this.ResolverStrategyForTransitives) else "") (if this.ResolverStrategyForDirectDependencies.IsSome then (sprintf "%O" this.ResolverStrategyForDirectDependencies) else "") this.Settings (if this.TransitivePrereleases then "TransitivePrereleases-true" else ""))
 
     member this.HasPackageSettings = String.IsNullOrWhiteSpace this.SettingString |> not

tests/Paket.Tests/Paket.Tests.fsproj

@@ -106,6 +106,7 @@
     <Compile Include="Resolver\AddingDependenciesSpecs.fs" />
     <Compile Include="Resolver\GlobalPessimisticStrategySpecs.fs" />
     <Compile Include="Resolver\GlobalOptimisticStrategySpecs.fs" />
+    <Compile Include="Resolver\GlobalKeepLatestPatchStrategySpecs.fs" />
     <Compile Include="Resolver\StrategySpecs.fs" />
     <Compile Include="Resolver\PropertyTestGenerators.fs" />
     <Compile Include="Resolver\PropertyTests.fs" />

tests/Paket.Tests/Resolver/DependencyGroupsAndRestrictions.fs

@@ -1,4 +1,4 @@
-module DependencyGroupsAndRestrictions
+module Paket.Resolver.DependencyGroupsAndRestrictions
 
 open Paket
 open NUnit.Framework

tests/Paket.Tests/Resolver/GlobalKeepLatestPatchStrategySpecs.fs

@@ -0,0 +1,128 @@
+module Paket.Resolver.GlobalKeepLatestPatchStrategySpecs
+
+open Paket
+open NUnit.Framework
+open FsUnit
+open TestHelpers
+open Paket.Domain
+open Paket.PackageResolver
+
+let resolve graph updateMode (cfg : DependenciesFile) =
+    let groups = [Constants.MainDependencyGroup, None ] |> Map.ofSeq
+    cfg.Resolve(true,noSha1,VersionsFromGraphAsSeq graph, (fun _ _ -> []),PackageDetailsFromGraph graph,(fun _ _ _ -> None),groups,updateMode).[Constants.MainDependencyGroup].ResolvedPackages.GetModelOrFail()
+
+let graph =
+  OfSimpleGraph [
+    "Nancy.Bootstrappers.Windsor","0.23",["Castle.Windsor",VersionRequirement(VersionRange.AtLeast "3.2.1",PreReleaseStatus.No)]
+    "Castle.Windsor","3.2.1",[]
+    "Castle.Windsor","3.2.2",[]
+    "Castle.Windsor","3.3.0",[]
+    "Castle.Windsor","4.1.0",[]
+  ]
+
+let config1 = sprintf """
+strategy %s
+source http://www.nuget.org/api/v2
+
+nuget Nancy.Bootstrappers.Windsor ~> 0.23
+"""
+
+[<Test>]
+let ``should resolve simple config1 with latest-patch``() =
+    let resolved =
+        DependenciesFile.FromSource(config1 "latest-patch")
+        |> resolve graph UpdateMode.UpdateAll
+    getVersion resolved.[PackageName "Castle.Windsor"] |> shouldEqual "3.2.2"
+    getVersion resolved.[PackageName "Nancy.Bootstrappers.Windsor"] |> shouldEqual "0.23"
+
+
+[<Test>]
+let ``should resolve simple config1 with latest-minor``() =
+    let resolved =
+        DependenciesFile.FromSource(config1 "latest-minor")
+        |> resolve graph UpdateMode.UpdateAll
+    getVersion resolved.[PackageName "Castle.Windsor"] |> shouldEqual "3.3.0"
+    getVersion resolved.[PackageName "Nancy.Bootstrappers.Windsor"] |> shouldEqual "0.23"
+
+let config2 = sprintf """
+strategy %s
+source http://www.nuget.org/api/v2
+
+nuget Castle.Windsor
+nuget Nancy.Bootstrappers.Windsor ~> 0.23
+"""
+
+[<Test>]
+let ``should resolve simple config2 with latest-patch``() =
+    let resolved =
+        DependenciesFile.FromSource(config2 "latest-patch")
+        |> resolve graph UpdateMode.UpdateAll
+    getVersion resolved.[PackageName "Castle.Windsor"] |> shouldEqual "3.2.2"
+    getVersion resolved.[PackageName "Nancy.Bootstrappers.Windsor"] |> shouldEqual "0.23"
+
+
+[<Test>]
+let ``should resolve simple config2 with latest-minor``() =
+    let resolved =
+        DependenciesFile.FromSource(config2 "latest-minor")
+        |> resolve graph UpdateMode.UpdateAll
+    getVersion resolved.[PackageName "Castle.Windsor"] |> shouldEqual "3.3.0"
+    getVersion resolved.[PackageName "Nancy.Bootstrappers.Windsor"] |> shouldEqual "0.23"
+
+let config3 = sprintf """
+strategy %s
+source http://www.nuget.org/api/v2
+
+nuget Nancy.Bootstrappers.Windsor ~> 0.23
+nuget Castle.Windsor
+"""
+
+[<Test>]
+let ``should resolve simple config3 with latest-patch``() =
+    let resolved =
+        DependenciesFile.FromSource(config3 "latest-patch")
+        |> resolve graph UpdateMode.UpdateAll
+    getVersion resolved.[PackageName "Castle.Windsor"] |> shouldEqual "3.2.2"
+    getVersion resolved.[PackageName "Nancy.Bootstrappers.Windsor"] |> shouldEqual "0.23"
+
+
+[<Test>]
+let ``should resolve simple config3 with latest-minor``() =
+    let resolved =
+        DependenciesFile.FromSource(config3 "latest-minor")
+        |> resolve graph UpdateMode.UpdateAll
+    getVersion resolved.[PackageName "Castle.Windsor"] |> shouldEqual "3.3.0"
+    getVersion resolved.[PackageName "Nancy.Bootstrappers.Windsor"] |> shouldEqual "0.23"
+
+let graph2 =
+  OfSimpleGraph [
+    "Nancy.Bootstrappers.Windsor","0.23",["Castle.Windsor",VersionRequirement(VersionRange.AtLeast "3.2.1",PreReleaseStatus.No)]
+    "Castle.Windsor","3.2.0",["Castle.Core",VersionRequirement(VersionRange.AtLeast "3.2.0",PreReleaseStatus.No)]
+    "Castle.Windsor","3.2.1",["Castle.Core",VersionRequirement(VersionRange.AtLeast "3.2.0",PreReleaseStatus.No)]
+    "Castle.Windsor","3.3.0",["Castle.Core",VersionRequirement(VersionRange.AtLeast "3.3.0",PreReleaseStatus.No)]
+    "Castle.Windsor-NLog","3.2.0.1",["Castle.Core-NLog",VersionRequirement(VersionRange.AtLeast "3.2.0",PreReleaseStatus.No)]
+    "Castle.Windsor-NLog","3.3.0",["Castle.Core-NLog",VersionRequirement(VersionRange.AtLeast "3.3.0",PreReleaseStatus.No)]
+    "Castle.Core-NLog","3.2.0",["Castle.Core",VersionRequirement(VersionRange.AtLeast "3.2.0",PreReleaseStatus.No)]
+    "Castle.Core-NLog","3.3.0",["Castle.Core",VersionRequirement(VersionRange.AtLeast "3.3.0",PreReleaseStatus.No)]
+    "Castle.Core-NLog","3.3.1",["Castle.Core",VersionRequirement(VersionRange.AtLeast "3.3.1",PreReleaseStatus.No)]
+    "Castle.Core","3.2.0",[]
+    "Castle.Core","3.2.1",[]
+    "Castle.Core","3.2.2",[]
+    "Castle.Core","3.3.0",[]
+    "Castle.Core","3.3.1",[]
+  ]
+
+let config5 = sprintf """
+strategy %s
+source http://www.nuget.org/api/v2
+
+nuget Nancy.Bootstrappers.Windsor !~> 0.23
+"""
+
+[<Test>]
+let ``should override global strategy with latest-patch``() =
+    let resolved =
+        DependenciesFile.FromSource(config5 "latest-patch")
+        |> resolve graph2 UpdateMode.UpdateAll
+    getVersion resolved.[PackageName "Castle.Windsor"] |> shouldEqual "3.2.1"
+    getVersion resolved.[PackageName "Nancy.Bootstrappers.Windsor"] |> shouldEqual "0.23"

tests/Paket.Tests/Resolver/GlobalOptimisticStrategySpecs.fs

@@ -1,4 +1,4 @@
-module GlobalOptimisticStrategySpecs
+module Paket.Resolver.GlobalOptimisticStrategySpecs
 
 open Paket
 open NUnit.Framework

tests/Paket.Tests/Resolver/ResolverErrorSituationTests.fs

@@ -1,4 +1,4 @@
-module ResolverErrorSituationTests
+module Paket.Resolver.ResolverErrorSituationTests
 
 open Paket
 open NUnit.Framework

tests/Paket.Tests/Resolver/StrategySpecs.fs

@@ -1,4 +1,4 @@
-module StrategySpecs
+module Paket.Resolver.StrategySpecs
 
 open Paket
 open NUnit.Framework