util/StringUtil: add StripRight() overload with "end" argument

src/client/ClientRead.cxx

@@ -22,7 +22,7 @@
 #include "Partition.hxx"
 #include "Instance.hxx"
 #include "event/Loop.hxx"
-#include "util/CharUtil.hxx"
+#include "util/StringUtil.hxx"
 
 #include <string.h>
 
@@ -39,11 +39,10 @@ Client::OnSocketInput(void *data, size_t length)
 	BufferedSocket::ConsumeInput(newline + 1 - p);
 
 	/* skip whitespace at the end of the line */
-	while (newline > p && IsWhitespaceFast(newline[-1]))
-		--newline;
+	char *end = StripRight(p, newline);
 
 	/* terminate the string at the end of the line */
-	*newline = 0;
+	*end = 0;
 
 	CommandResult result = client_process_line(*this, p);
 	switch (result) {

src/fs/StandardDirectory.cxx

@@ -40,7 +40,6 @@
 #endif
 
 #ifdef USE_XDG
-#include "util/CharUtil.hxx"
 #include "util/StringUtil.hxx"
 #include "TextFile.hxx"
 #include <string.h>
@@ -169,9 +168,7 @@ ParseConfigLine(char *line, const char *dir_name, AllocatedPath &result_dir)
 		if (line_end == nullptr)
 			return true;
 	} else {
-		line_end = line + strlen(line);
-		while (line < line_end && IsWhitespaceNotNull(line_end[-1]))
-			--line_end;
+		line_end = StripRight(line, line + strlen(line));
 	}
 
 	// check for empty result

src/input/TextInputStream.cxx

@@ -20,7 +20,7 @@
 #include "config.h"
 #include "TextInputStream.hxx"
 #include "InputStream.hxx"
-#include "util/CharUtil.hxx"
+#include "util/StringUtil.hxx"
 #include "util/Error.hxx"
 #include "Log.hxx"
 
@@ -72,8 +72,7 @@ TextInputStream::ReadLine()
 
 	buffer.Consume(p - src + 1);
 
-	while (p > src && IsWhitespaceFast(p[-1]))
-		--p;
-	*p = 0;
+	char *end = StripRight(src, p);
+	*end = 0;
 	return src;
 }

src/input/plugins/CurlInputPlugin.cxx

@@ -31,7 +31,7 @@
 #include "event/Call.hxx"
 #include "IOThread.hxx"
 #include "util/ASCII.hxx"
-#include "util/CharUtil.hxx"
+#include "util/StringUtil.hxx"
 #include "util/NumberParser.hxx"
 #include "util/CircularBuffer.hxx"
 #include "util/HugeAllocator.hxx"
@@ -661,11 +661,8 @@ input_curl_headerfunction(void *ptr, size_t size, size_t nmemb, void *stream)
 
 	/* strip the value */
 
-	while (value < end && IsWhitespaceOrNull(*value))
-		++value;
-
-	while (end > value && IsWhitespaceOrNull(end[-1]))
-		--end;
+	value = StripLeft(value, end);
+	end = StripRight(value, end);
 
 	c.HeaderReceived(name, std::string(value, end));
 	return size;

src/util/StringUtil.cxx

@@ -35,6 +35,24 @@ StripLeft(const char *p)
 	return p;
 }
 
+const char *
+StripLeft(const char *p, const char *end)
+{
+	while (p < end && IsWhitespaceOrNull(*p))
+		++p;
+
+	return p;
+}
+
+const char *
+StripRight(const char *p, const char *end)
+{
+	while (end > p && IsWhitespaceOrNull(end[-1]))
+		--end;
+
+	return end;
+}
+
 size_t
 StripRight(const char *p, size_t length)
 {

src/util/StringUtil.hxx

@@ -39,6 +39,28 @@ StripLeft(char *p)
 	return const_cast<char *>(StripLeft((const char *)p));
 }
 
+gcc_pure
+const char *
+StripLeft(const char *p, const char *end);
+
+/**
+ * Determine the string's end as if it was stripped on the right side.
+ */
+gcc_pure
+const char *
+StripRight(const char *p, const char *end);
+
+/**
+ * Determine the string's end as if it was stripped on the right side.
+ */
+gcc_pure
+static inline char *
+StripRight(char *p, char *end)
+{
+	return const_cast<char *>(StripRight((const char *)p,
+					     (const char *)end));
+}
+
 /**
  * Determine the string's length as if it was stripped on the right
  * side.