From 7673b76970dd9ca15eac076c4995195522f48f00 Mon Sep 17 00:00:00 2001
From: Markus Scherer <markus.icu@gmail.com>
Date: Fri, 21 Nov 2003 18:35:16 +0000
Subject: [PATCH] ICU-2235 make udata_open() work with opposite-endian data

X-SVN-Rev: 13813
---
 icu4c/source/common/ucmndata.c | 31 +++++++++++++++++++++++++++++--
 icu4c/source/common/ucmndata.h | 19 ++++++++++++++++++-
 icu4c/source/common/udata.c    | 15 ++++++++++-----
 icu4c/source/common/udatamem.c |  4 ++--
 4 files changed, 59 insertions(+), 10 deletions(-)

diff --git a/icu4c/source/common/ucmndata.c b/icu4c/source/common/ucmndata.c
index 0ac16c554fb..caa2d2c9483 100644
--- a/icu4c/source/common/ucmndata.c
+++ b/icu4c/source/common/ucmndata.c
@@ -26,6 +26,33 @@
 #include "ucmndata.h"
 #include "udatamem.h"
 
+U_CFUNC uint16_t
+udata_getHeaderSize(const DataHeader *udh) {
+    if(udh==NULL) {
+        return 0;
+    } else if(udh->info.isBigEndian==U_IS_BIG_ENDIAN) {
+        /* same endianness */
+        return udh->dataHeader.headerSize;
+    } else {
+        /* opposite endianness */
+        uint16_t x=udh->dataHeader.headerSize;
+        return (uint16_t)((x<<8)|(x>>8));
+    }
+}
+
+U_CFUNC uint16_t
+udata_getInfoSize(const UDataInfo *info) {
+    if(info==NULL) {
+        return 0;
+    } else if(info->isBigEndian==U_IS_BIG_ENDIAN) {
+        /* same endianness */
+        return info->size;
+    } else {
+        /* opposite endianness */
+        uint16_t x=info->size;
+        return (uint16_t)((x<<8)|(x>>8));
+    }
+}
 
 /*----------------------------------------------------------------------------------*
  *                                                                                  *
@@ -199,7 +226,7 @@ void udata_checkCommonData(UDataMemory *udm, UErrorCode *err) {
         ) {
         /* dataFormat="CmnD" */
         udm->vFuncs = &CmnDFuncs;
-        udm->toc=(const char *)udm->pHeader+udm->pHeader->dataHeader.headerSize;
+        udm->toc=(const char *)udm->pHeader+udata_getHeaderSize(udm->pHeader);
     }
     else if(udm->pHeader->info.dataFormat[0]==0x54 &&
         udm->pHeader->info.dataFormat[1]==0x6f &&
@@ -209,7 +236,7 @@ void udata_checkCommonData(UDataMemory *udm, UErrorCode *err) {
         ) {
         /* dataFormat="ToCP" */
         udm->vFuncs = &ToCPFuncs;
-        udm->toc=(const char *)udm->pHeader+udm->pHeader->dataHeader.headerSize;
+        udm->toc=(const char *)udm->pHeader+udata_getHeaderSize(udm->pHeader);
     }
     else {
         /* dataFormat not recognized */
diff --git a/icu4c/source/common/ucmndata.h b/icu4c/source/common/ucmndata.h
index 886ef32055b..9634ed840f6 100644
--- a/icu4c/source/common/ucmndata.h
+++ b/icu4c/source/common/ucmndata.h
@@ -50,9 +50,26 @@ typedef struct {
 
 typedef struct {
     uint32_t count;
-    UDataOffsetTOCEntry entry[2];    /* Acutal size of array is from count. */
+    UDataOffsetTOCEntry entry[2];    /* Actual size of array is from count. */
 } UDataOffsetTOC;
 
+/**
+ * Get the header size from a const DataHeader *udh.
+ * Handles opposite-endian data.
+ *
+ * @internal
+ */
+U_CFUNC uint16_t
+udata_getHeaderSize(const DataHeader *udh);
+
+/**
+ * Get the UDataInfo.size from a const UDataInfo *info.
+ * Handles opposite-endian data.
+ *
+ * @internal
+ */
+U_CFUNC uint16_t
+udata_getInfoSize(const UDataInfo *info);
 
 /*
  *  "Virtual" functions for data lookup.
diff --git a/icu4c/source/common/udata.c b/icu4c/source/common/udata.c
index e95dc8378c1..67f0bf5e7e3 100644
--- a/icu4c/source/common/udata.c
+++ b/icu4c/source/common/udata.c
@@ -874,9 +874,8 @@ checkDataItem
 
     if(pHeader->dataHeader.magic1==0xda &&
         pHeader->dataHeader.magic2==0x27 &&
-        pHeader->info.isBigEndian==U_IS_BIG_ENDIAN &&
         (isAcceptable==NULL || isAcceptable(context, type, name, &pHeader->info))
-        ) {
+    ) {
         rDataMem=UDataMemory_createNewInstance(fatalErr);
         if (U_FAILURE(*fatalErr)) {
             return NULL;
@@ -1165,10 +1164,16 @@ udata_getInfo(UDataMemory *pData, UDataInfo *pInfo) {
     if(pInfo!=NULL) {
         if(pData!=NULL && pData->pHeader!=NULL) {
             const UDataInfo *info=&pData->pHeader->info;
-            if(pInfo->size>info->size) {
-                pInfo->size=info->size;
+            uint16_t dataInfoSize=udata_getInfoSize(info);
+            if(pInfo->size>dataInfoSize) {
+                pInfo->size=dataInfoSize;
+            }
+            uprv_memcpy((uint16_t *)pInfo+1, (const uint16_t *)info+1, pInfo->size-2);
+            if(info->isBigEndian!=U_IS_BIG_ENDIAN) {
+                /* opposite endianness */
+                uint16_t x=info->reservedWord;
+                pInfo->reservedWord=(uint16_t)((x<<8)|(x>>8));
             }
-            uprv_memcpy((uint16_t *)pInfo+1, (uint16_t *)info+1, pInfo->size-2);
         } else {
             pInfo->size=0;
         }
diff --git a/icu4c/source/common/udatamem.c b/icu4c/source/common/udatamem.c
index 06a5308745b..220ee5a3124 100644
--- a/icu4c/source/common/udatamem.c
+++ b/icu4c/source/common/udatamem.c
@@ -101,7 +101,7 @@ udata_close(UDataMemory *pData) {
 U_CAPI const void * U_EXPORT2
 udata_getMemory(UDataMemory *pData) {
     if(pData!=NULL && pData->pHeader!=NULL) {
-        return (char *)(pData->pHeader)+pData->pHeader->dataHeader.headerSize;
+        return (char *)(pData->pHeader)+udata_getHeaderSize(pData->pHeader);
     } else {
         return NULL;
     }
@@ -134,7 +134,7 @@ udata_getLength(UDataMemory *pData) {
          * subtract the header size,
          * return only the size of the actual data starting at udata_getMemory()
          */
-        return pData->length-pData->pHeader->dataHeader.headerSize;
+        return pData->length-udata_getHeaderSize(pData->pHeader);
     } else {
         return -1;
     }