add IsChildOf, and dougt's relative-path-handling diff

xpcom/io/nsFileSpec.cpp

@@ -1023,6 +1023,42 @@ const char* nsFileSpec::GetCString() const
 }
 #endif
 
+/* Is our spec a child of the provided parent? */
+PRBool
+nsFileSpec::IsChildOf(nsFileSpec &possibleParent)
+{
+    nsFileSpec iter = *this, parent;
+#ifdef DEBUG
+    int depth = 0;
+#endif
+    while (1) {
+#ifdef DEBUG
+        // sanity
+        NS_ASSERTION(depth < 100, "IsChildOf has lost its little mind");
+        if (depth > 100)
+            return PR_FALSE;
+#endif
+        if (iter == possibleParent)
+            return PR_TRUE;
+
+        iter.GetParent(parent); // shouldn't this be an error on parent?
+        if (iter.Failed())
+            return PR_FALSE;
+
+        if (iter == parent)     // hit bottom
+            return PR_FALSE;
+        
+        iter = parent;
+#ifdef DEBUG
+        depth++;
+#endif
+    }
+
+    /* not reached, but I bet some compiler will whine */
+    return PR_FALSE;
+}
+
+
 //========================================================================================
 //    class nsPersistentFileDescriptor
 //========================================================================================

xpcom/io/nsFileSpec.h

@@ -332,6 +332,7 @@ class NS_COM nsFileSpec
                                     // so do not delete (or free) it. See also nsNSPRPath below,
                                     // if you really must pass a string  to PR_OpenFile().
                                     // Doing so will introduce two automatic bugs.
+       PRBool                     IsChildOf(nsFileSpec &possibleParent);
 
 #ifdef XP_MAC
         // For Macintosh people, this is meant to be useful in its own right as a C++ version

xpcom/io/nsFileSpecImpl.cpp

@@ -80,6 +80,15 @@ NS_IMETHODIMP nsFileSpecImpl::FromFileSpec(const nsIFileSpec *original)
 	return mFileSpec.Error();
 }
 
+//----------------------------------------------------------------------------------------
+NS_IMETHODIMP nsFileSpecImpl::IsChildOf(nsIFileSpec *possibleParent,
+                                        PRBool *_retval)
+{
+  *_retval = mFileSpec.IsChildOf(FILESPEC(possibleParent));
+  return mFileSpec.Error();
+}
+//----------------------------------------------------------------------------------------
+
 //----------------------------------------------------------------------------------------
 NS_IMETHODIMP nsFileSpecImpl::GetURLString(char * *aURLString)
 //----------------------------------------------------------------------------------------

xpcom/io/nsFileSpecUnix.cpp

@@ -84,44 +84,21 @@ void nsFileSpecHelpers::Canonify(nsSimpleCharString& ioPath, PRBool inMakeDirs)
         const mode_t mode = 0700;
         nsFileSpecHelpers::MakeAllDirectories((const char*)ioPath, mode);
     }
-    char buffer[MAXPATHLEN];
-    errno = 0;
-#if defined(SOLARIS)
-    memset(buffer, '\0', sizeof(buffer)); // realpath reads it all, initialized or not.
-#else
-    *buffer = '\0';
-#endif
-    char* canonicalPath = realpath((const char*)ioPath, buffer);
-    if (!canonicalPath)
+
+    errno = 0;  // needed?
+
+    if (ioPath[0] != '/')
     {
-        // Linux's realpath() is pathetically buggy.  If the reason for the nil
-        // result is just that the leaf does not exist, strip the leaf off,
-        // process that, and then add the leaf back.
-        nsSimpleCharString allButLeaf(ioPath);
-        if (allButLeaf.IsEmpty())
-            return;
-        char* lastSeparator = strrchr((char*)allButLeaf, '/');
-        if (lastSeparator)
-        {
-            *lastSeparator = '\0';
-            canonicalPath = realpath((const char*)allButLeaf, buffer);
-            strcat(buffer, "/");
-            // Add back the leaf
-            strcat(buffer, ++lastSeparator);
-        }
+        // the ioPath that was passed in is relative.  We must cat it to the cwd.
+        char buffer[MAXPATHLEN];
+
+        (void) getcwd(buffer, MAXPATHLEN);
+
+        strcat(buffer, "/");
+        strcat(buffer, ioPath);
+
+        ioPath = buffer;
     }
-    if (!canonicalPath && ioPath[0] != '/' && !inMakeDirs)
-    {
-        // Well, if it's a relative path, hack it ourselves.
-        canonicalPath = realpath(".", buffer);
-        if (canonicalPath)
-        {
-            strcat(canonicalPath, "/");
-            strcat(canonicalPath, ioPath);
-        }
-    }
-    if (canonicalPath)
-        ioPath = canonicalPath;
 } // nsFileSpecHelpers::Canonify
 
 //----------------------------------------------------------------------------------------

xpcom/io/nsIFileSpec.idl

@@ -68,6 +68,7 @@ interface nsIFileSpec : nsISupports
 	readonly attribute nsIFileSpec parent;
 	readonly attribute nsIInputStream inputStream;
 	readonly attribute nsIOutputStream outputStream;
+    boolean isChildOf(in nsIFileSpec possibleParent);
 	[noscript] readonly attribute nsFileSpec fileSpec;
 	[noscript] void setFromFileSpec([const] in nsFileSpecRef spec);