From 65025e913246597a385252172275420e7f89be3f Mon Sep 17 00:00:00 2001
From: Alex Arslan <ararslan@comcast.net>
Date: Thu, 11 May 2023 16:20:09 -0700
Subject: [PATCH 1/2] Fix `rand` for truncated normal with 0 variance

Fixes issues 1712 and 1867.
---
 src/truncated/normal.jl  | 18 +++++++++++++-----
 test/truncated/normal.jl | 14 +++++++++++++-
 2 files changed, 26 insertions(+), 6 deletions(-)

diff --git a/src/truncated/normal.jl b/src/truncated/normal.jl
index 6fb334273..904195971 100644
--- a/src/truncated/normal.jl
+++ b/src/truncated/normal.jl
@@ -128,14 +128,22 @@ function rand(rng::AbstractRNG, d::Truncated{<:Normal{<:Real},Continuous})
     d0 = d.untruncated
     μ = mean(d0)
     σ = std(d0)
+    a, b = extrema(d)
     if isfinite(μ)
-        lower, upper = extrema(d)
-        a = (lower - μ) / σ
-        b = (upper - μ) / σ
-        z = randnt(rng, a, b, d.tp)
+        if iszero(σ)
+            if a <= μ <= b
+                z = 0.0
+            else
+                throw(ArgumentError("cannot sample from distribution with 0 mass"))
+            end
+        else
+            a′ = (a - μ) / σ
+            b′ = (b - μ) / σ
+            z = randnt(rng, a′, b′, d.tp)
+        end
         return μ + σ * z
     else
-        return clamp(μ, extrema(d)...)
+        return clamp(μ, a, b)
     end
 end
 
diff --git a/test/truncated/normal.jl b/test/truncated/normal.jl
index 9d287c026..5850c5912 100644
--- a/test/truncated/normal.jl
+++ b/test/truncated/normal.jl
@@ -47,7 +47,7 @@ end
         [(r = rand, r! = rand!),
          (r = ((d, n) -> rand(rng, d, n)), r! = ((d, X) -> rand!(rng, d, X)))]
         repeats = 1000000
-        
+
         @test abs(mean(func.r(trunc, repeats))) < 0.01
         @test abs(median(func.r(trunc, repeats))) < 0.01
         @test abs(var(func.r(trunc, repeats)) - var(trunc)) < 0.01
@@ -69,3 +69,15 @@ end
         @test isfinite(pdf(trunc, x))
     end
 end
+
+@testset "Degenerate truncated normal" begin
+    # https://github.com/JuliaStats/Distributions.jl/issues/1712
+    d = Normal(2, 0)
+    @test rand(truncated(d, 2, 2)) == 2    # a == μ == b
+    @test rand(truncated(d, 1, 3)) == 2    # a <= μ <= b
+    @test_throws ArgumentError rand(truncated(d, 6, 9))  # μ ∉ [a, b]
+    # https://github.com/JuliaStats/Distributions.jl/issues/1867
+    d = Normal(1, 0)
+    @test rand(truncated(Normal(1, 0), 0, 1)) == 1
+    @test rand(truncated(Normal(0, 0), 0, 1)) == 0
+end

From 5c79db14e9de4da60e85f28aec2987bb2ca9489d Mon Sep 17 00:00:00 2001
From: Alex Arslan <ararslan@comcast.net>
Date: Thu, 15 Aug 2024 10:06:38 -0700
Subject: [PATCH 2/2] Bump patch version

---
 Project.toml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Project.toml b/Project.toml
index c05283276..af12e4b7a 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,7 +1,7 @@
 name = "Distributions"
 uuid = "31c24e10-a181-5473-b8eb-7969acd0382f"
 authors = ["JuliaStats"]
-version = "0.25.110"
+version = "0.25.111"
 
 [deps]
 AliasTables = "66dad0bd-aa9a-41b7-9441-69ab47430ed8"