fix(textprocessing): improve case merging logic

examples/benchmark.jl

@@ -1,4 +1,6 @@
 #md# Test the performance of different trainers
+#md# <details>
+#md# 
 using WordCloud
 using Random
 # Random.seed!(8)
@@ -37,3 +39,5 @@ for (i, (wc, e)) in enumerate(zip(wcs, es))
     println("##$(i - 1) $(length(wc))@$(size(wc.mask)):")
     println(repr("text/plain", e))
 end
+#md# </details>
+#md# 

src/textprocessing.jl

@@ -141,9 +141,12 @@ end
 function casemerge!(d)
     for w in keys(d)
         if length(w) > 0 && isuppercase(w[1]) && islowercase(w[end])
-            lw = lowercase(w)
-            if lw != w && lw in keys(d) && d[lw] > d[w]
-                d[lw] += d[w]
+            w2 = lowercase(w)
+            if w2 != w && w2 in keys(d)
+                if d[w2] < d[w]
+                    w, w2 = w2, w
+                end
+                d[w2] += d[w]
                 pop!(d, w)
             end
         end

test/runtests.jl

@@ -112,7 +112,7 @@ include("test_textprocessing.jl")
             angles=(0, 90));
     rescale!(wc, 1.23)
     @test getwords(wc, WordCloud.ID(2)) == words[2]
-    pin(wc, ["head", "cat"]) do 
+    pin(wc, ["head", "voice"]) do 
         @test length(wc) == 298
         setpositions!(wc, 1, (2, 2))
         setpositions!(wc, [1, "Alice", "eye"], (-1, -2))