Util/ASCII: add StringEqualsCaseASCII() overload with length

src/decoder/FlacMetadata.cxx

@@ -25,6 +25,7 @@
 #include "tag/TagTable.hxx"
 #include "tag/TagBuilder.hxx"
 #include "ReplayGainInfo.hxx"
+#include "util/ASCII.hxx"
 
 #include <glib.h>
 
@@ -135,7 +136,7 @@ flac_comment_value(const FLAC__StreamMetadata_VorbisComment_Entry *entry,
 	const char *comment = (const char*)entry->entry;
 
 	if (entry->length <= name_length ||
-	    g_ascii_strncasecmp(comment, name, name_length) != 0)
+	    StringEqualsCaseASCII(comment, name, name_length))
 		return nullptr;
 
 	if (comment[name_length] == '=') {

src/decoder/VorbisComments.cxx

@@ -25,6 +25,7 @@
 #include "tag/TagHandler.hxx"
 #include "tag/TagBuilder.hxx"
 #include "ReplayGainInfo.hxx"
+#include "util/ASCII.hxx"
 
 #include <glib.h>
 
@@ -38,7 +39,7 @@ vorbis_comment_value(const char *comment, const char *needle)
 {
 	size_t len = strlen(needle);
 
-	if (g_ascii_strncasecmp(comment, needle, len) == 0 &&
+	if (StringEqualsCaseASCII(comment, needle, len) &&
 	    comment[len] == '=')
 		return comment + len + 1;
 

src/mixer/OssMixerPlugin.cxx

@@ -21,12 +21,11 @@
 #include "MixerInternal.hxx"
 #include "OutputAPI.hxx"
 #include "system/fd_util.h"
+#include "util/ASCII.hxx"
 #include "util/Error.hxx"
 #include "util/Domain.hxx"
 #include "Log.hxx"
 
-#include <glib.h>
-
 #include <assert.h>
 #include <string.h>
 #include <sys/stat.h>
@@ -71,7 +70,7 @@ oss_find_mixer(const char *name)
 	size_t name_length = strlen(name);
 
 	for (unsigned i = 0; i < SOUND_MIXER_NRDEVICES; i++) {
-		if (g_ascii_strncasecmp(name, labels[i], name_length) == 0 &&
+		if (StringEqualsCaseASCII(name, labels[i], name_length) &&
 		    (labels[i][name_length] == 0 ||
 		     labels[i][name_length] == ' '))
 			return i;

src/output/HttpdClient.cxx

@@ -20,7 +20,7 @@
 #include "config.h"
 #include "HttpdClient.hxx"
 #include "HttpdInternal.hxx"
-#include "util/fifo_buffer.h"
+#include "util/ASCII.hxx"
 #include "Page.hxx"
 #include "IcyMetaDataServer.hxx"
 #include "system/SocketError.hxx"
@@ -102,13 +102,13 @@ HttpdClient::HandleLine(const char *line)
 			return true;
 		}
 
-		if (g_ascii_strncasecmp(line, "Icy-MetaData: 1", 15) == 0) {
+		if (StringEqualsCaseASCII(line, "Icy-MetaData: 1", 15)) {
 			/* Send icy metadata */
 			metadata_requested = metadata_supported;
 			return true;
 		}
 
-		if (g_ascii_strncasecmp(line, "transferMode.dlna.org: Streaming", 32) == 0) {
+		if (StringEqualsCaseASCII(line, "transferMode.dlna.org: Streaming", 32)) {
 			/* Send as dlna */
 			dlna_streaming_requested = true;
 			/* metadata is not supported by dlna streaming, so disable it */

src/pcm/PcmResampleLibsamplerate.cxx

@@ -19,12 +19,11 @@
 
 #include "config.h"
 #include "PcmResampleInternal.hxx"
+#include "util/ASCII.hxx"
 #include "util/Error.hxx"
 #include "util/Domain.hxx"
 #include "Log.hxx"
 
-#include <glib.h>
-
 #include <assert.h>
 #include <stdlib.h>
 #include <string.h>
@@ -54,7 +53,7 @@ lsr_parse_converter(const char *s)
 		if (name == nullptr)
 			break;
 
-		if (g_ascii_strncasecmp(s, name, length) == 0) {
+		if (StringEqualsCaseASCII(s, name, length)) {
 			lsr_converter = i;
 			return true;
 		}

src/util/ASCII.hxx

@@ -51,4 +51,16 @@ StringEqualsCaseASCII(const char *a, const char *b)
   return strcasecmp(a, b) == 0;
 }
 
+gcc_pure gcc_nonnull_all
+static inline bool
+StringEqualsCaseASCII(const char *a, const char *b, size_t n)
+{
+  assert(a != nullptr);
+  assert(b != nullptr);
+
+  /* note: strcasecmp() depends on the locale, but for ASCII-only
+     strings, it's safe to use */
+  return strncasecmp(a, b, n) == 0;
+}
+
 #endif