3 files changed, 16 insertions, 7 deletions
diff --git a/custom/extensions/syntax-highlight.lua b/custom/extensions/syntax-highlight.lua
index 282b0cf..7414b63 100644
--- a/custom/extensions/syntax-highlight.lua
+++ b/custom/extensions/syntax-highlight.lua
@@ -153,9 +153,11 @@ local function load_scintillua()
 end
 
 -- The first line goes along to detect(), so a script with no extension is
--- still known by its shebang.
+-- still known by its shebang. detect() matches an extension by its case, so
+-- a name in capitals such as MAIN.C is tried again in lower case.
 local function lexer_for(name, text)
-	local lang = scintillua.detect(name, string.match(text, "^[^\n]*"))
+	local first = string.match(text, "^[^\n]*")
+	local lang = scintillua.detect(name, first) or scintillua.detect(string.lower(name), first)
 	return lang and scintillua.load(lang)
 end
 
diff --git a/tests/extensions/fake-lexers/lexer.lua b/tests/extensions/fake-lexers/lexer.lua
index dd7545f..bb869de 100644
--- a/tests/extensions/fake-lexers/lexer.lua
+++ b/tests/extensions/fake-lexers/lexer.lua
@@ -1,9 +1,10 @@
 -- A miniature stand-in for the Scintillua lexer module, just enough for the
 -- syntax-highlight checks to drive every path through the filter without the
--- real collection installed. detect() names a lexer after the filename's
--- suffix, or fake for a shebang naming it, and load() hands out the toy lexer
--- of that name. Besides fake there is one that stops short and one that
--- raises, and any other name fails to load.
+-- real collection installed. detect() answers for the suffixes it knows,
+-- matched by case as Scintillua's own does, or fake for a shebang naming it,
+-- and load() hands out the toy lexer of that name. Besides fake there is one
+-- that stops short and one that raises, and python, which detect() knows but
+-- load() cannot find, as a collection missing a lexer would answer.
 
 local M = {}
 
@@ -67,11 +68,13 @@ function M.load(name)
 	return lexer
 end
 
+local suffixes = { fake = "fake", short = "short", badlex = "badlex", py = "python" }
+
 function M.detect(filename, line)
 	if line ~= nil and line:match("^#!.*fake") then
 		return "fake"
 	end
-	return filename:match("%.([^.]+)$")
+	return suffixes[filename:match("%.([^.]+)$") or ""]
 end
 
 return M
diff --git a/tests/extensions/test-syntax-highlight.lua b/tests/extensions/test-syntax-highlight.lua
index 5fc6ea3..a0debc6 100644
--- a/tests/extensions/test-syntax-highlight.lua
+++ b/tests/extensions/test-syntax-highlight.lua
@@ -70,6 +70,10 @@ h.equals("a lexer stopping early leaves an escaped tail", out, "<span class='hl-
 out = render("boom.badlex", "some <code>")
 h.equals("a lexer that raises falls back to escaped text", out, "some &lt;code&gt;")
 
+out = render("HELLO.FAKE", "if 42")
+h.contains("an extension in capitals finds its lexer", out,
+	"<span class='hl-keyword'>if</span>")
+
 out = render("post-receive", "#!/usr/bin/fake\nif")
 h.contains("a shebang picks the lexer of a file with no extension", out,
 	"<span class='hl-keyword'>if</span>")
-rw-r--r--	custom/extensions/syntax-highlight.lua	6
-rw-r--r--	tests/extensions/fake-lexers/lexer.lua	13
-rw-r--r--	tests/extensions/test-syntax-highlight.lua	4