diff --git a/mozilla/js/js2/hash.cpp b/mozilla/js/js2/hash.cpp
index 214a420cc57..b0504320d87 100644
--- a/mozilla/js/js2/hash.cpp
+++ b/mozilla/js/js2/hash.cpp
@@ -63,7 +63,7 @@ JS::HashNumber JS::hashString(const String &s)
 //
 
 
-static const int minLgNBuckets = 4;
+const uint minLgNBuckets = 4;
 
 
 JS::GenericHashTableIterator::GenericHashTableIterator(GenericHashTable &ht):
@@ -164,7 +164,7 @@ void JS::GenericHashTable::rehash()
 		bucketsEnd = newBucketsEnd;
 	} catch (std::bad_alloc) {
 		// Out of memory.  Ignore the error and just relax the resizing boundaries.
-		if (JS_BIT(newLgNBuckets) > bucketsEnd - buckets)
+		if (buckets + JS_BIT(newLgNBuckets) > bucketsEnd)
 			maxNEntries >>= 1;
 		else
 			minNEntries <<= 1;
diff --git a/mozilla/js/js2/numerics.cpp b/mozilla/js/js2/numerics.cpp
index 72e3b703308..ae57e4f97ca 100644
--- a/mozilla/js/js2/numerics.cpp
+++ b/mozilla/js/js2/numerics.cpp
@@ -1914,8 +1914,7 @@ static char *doubleToAscii(double d, int mode, bool biasUp, int ndigits,
     if ((word0(d) & Exp_mask) == Exp_mask) {
         // Infinity or NaN
         *decpt = 9999;
-        s = !word1(d) && !(word0(d) & Frac_mask) ? "Infinity" : "NaN";
-        strcpy(buf, s);
+        strcpy(buf, !word1(d) && !(word0(d) & Frac_mask) ? "Infinity" : "NaN");
         return buf[3] ? buf + 8 : buf + 3;
     }
     if (!d) {
diff --git a/mozilla/js/js2/systemtypes.h b/mozilla/js/js2/systemtypes.h
index bbe7ef75710..0d5a5d12a8e 100644
--- a/mozilla/js/js2/systemtypes.h
+++ b/mozilla/js/js2/systemtypes.h
@@ -61,11 +61,17 @@ typedef float float32;
 // Use wchar_t on platforms on which wchar_t has 16 bits; otherwise use int16.
 // Note that in C++ wchar_t is a distinct type rather than a typedef for some integral type.
 // Like char, a char16 can be either signed or unsigned at the implementation's discretion.
-typedef wchar_t char16;
-#ifndef _WIN32 // Microsoft VC6 bug: wchar_t should be a built-in type, not a typedef
- typedef unsigned wchar_t uchar16;
+#ifdef __GNUC__
+ // GCC's wchar_t is 32 bits, so we can't use it.
+ typedef uint16 char16;
+ typedef uint16 uchar16;
 #else
- typedef wchar_t uchar16;
+ typedef wchar_t char16;
+ #ifndef _WIN32 // Microsoft VC6 bug: wchar_t should be a built-in type, not a typedef
+  typedef unsigned wchar_t uchar16;
+ #else
+  typedef wchar_t uchar16;
+ #endif
 #endif
 
 #ifdef _WIN32
diff --git a/mozilla/js/js2/utilities.h b/mozilla/js/js2/utilities.h
index 3685bce8822..7f2019c1e84 100644
--- a/mozilla/js/js2/utilities.h
+++ b/mozilla/js/js2/utilities.h
@@ -356,9 +356,11 @@ namespace JavaScript {
 	// A class to remember the format of an ostream so that a function may modify it internally
 	// without changing it for the caller.
 	class SaveFormat {
+#ifndef __GNUC__ // The GCC libraries don't support ios_base yet.
 		ostream &o;
 		std::ios_base::fmtflags flags;
 		char fill;
+#endif
 	  public:
 		explicit SaveFormat(ostream &out);
 		~SaveFormat();
diff --git a/mozilla/js2/src/hash.cpp b/mozilla/js2/src/hash.cpp
index 214a420cc57..b0504320d87 100644
--- a/mozilla/js2/src/hash.cpp
+++ b/mozilla/js2/src/hash.cpp
@@ -63,7 +63,7 @@ JS::HashNumber JS::hashString(const String &s)
 //
 
 
-static const int minLgNBuckets = 4;
+const uint minLgNBuckets = 4;
 
 
 JS::GenericHashTableIterator::GenericHashTableIterator(GenericHashTable &ht):
@@ -164,7 +164,7 @@ void JS::GenericHashTable::rehash()
 		bucketsEnd = newBucketsEnd;
 	} catch (std::bad_alloc) {
 		// Out of memory.  Ignore the error and just relax the resizing boundaries.
-		if (JS_BIT(newLgNBuckets) > bucketsEnd - buckets)
+		if (buckets + JS_BIT(newLgNBuckets) > bucketsEnd)
 			maxNEntries >>= 1;
 		else
 			minNEntries <<= 1;
diff --git a/mozilla/js2/src/numerics.cpp b/mozilla/js2/src/numerics.cpp
index 72e3b703308..ae57e4f97ca 100644
--- a/mozilla/js2/src/numerics.cpp
+++ b/mozilla/js2/src/numerics.cpp
@@ -1914,8 +1914,7 @@ static char *doubleToAscii(double d, int mode, bool biasUp, int ndigits,
     if ((word0(d) & Exp_mask) == Exp_mask) {
         // Infinity or NaN
         *decpt = 9999;
-        s = !word1(d) && !(word0(d) & Frac_mask) ? "Infinity" : "NaN";
-        strcpy(buf, s);
+        strcpy(buf, !word1(d) && !(word0(d) & Frac_mask) ? "Infinity" : "NaN");
         return buf[3] ? buf + 8 : buf + 3;
     }
     if (!d) {
diff --git a/mozilla/js2/src/systemtypes.h b/mozilla/js2/src/systemtypes.h
index bbe7ef75710..0d5a5d12a8e 100644
--- a/mozilla/js2/src/systemtypes.h
+++ b/mozilla/js2/src/systemtypes.h
@@ -61,11 +61,17 @@ typedef float float32;
 // Use wchar_t on platforms on which wchar_t has 16 bits; otherwise use int16.
 // Note that in C++ wchar_t is a distinct type rather than a typedef for some integral type.
 // Like char, a char16 can be either signed or unsigned at the implementation's discretion.
-typedef wchar_t char16;
-#ifndef _WIN32 // Microsoft VC6 bug: wchar_t should be a built-in type, not a typedef
- typedef unsigned wchar_t uchar16;
+#ifdef __GNUC__
+ // GCC's wchar_t is 32 bits, so we can't use it.
+ typedef uint16 char16;
+ typedef uint16 uchar16;
 #else
- typedef wchar_t uchar16;
+ typedef wchar_t char16;
+ #ifndef _WIN32 // Microsoft VC6 bug: wchar_t should be a built-in type, not a typedef
+  typedef unsigned wchar_t uchar16;
+ #else
+  typedef wchar_t uchar16;
+ #endif
 #endif
 
 #ifdef _WIN32
diff --git a/mozilla/js2/src/utilities.h b/mozilla/js2/src/utilities.h
index 3685bce8822..7f2019c1e84 100644
--- a/mozilla/js2/src/utilities.h
+++ b/mozilla/js2/src/utilities.h
@@ -356,9 +356,11 @@ namespace JavaScript {
 	// A class to remember the format of an ostream so that a function may modify it internally
 	// without changing it for the caller.
 	class SaveFormat {
+#ifndef __GNUC__ // The GCC libraries don't support ios_base yet.
 		ostream &o;
 		std::ios_base::fmtflags flags;
 		char fill;
+#endif
 	  public:
 		explicit SaveFormat(ostream &out);
 		~SaveFormat();