Apply to AmberTools release cantidate 2010-03-28
cd $AMBERHOME/src/ptraj
patch -p0 -N -r patch_rejects < ptraj.c.singleFrame.patch

Author: Daniel R. Roe
Date: 2010-03-29
Description:
Fixes bug where ptraj would not correctly recognize AMBER trajectories 
of length 1 without box coordinates. 
-----------------------------------------------------------------------------
--- ptraj.c	2010-03-29 17:48:28.000000000 -0400
+++ ptraj.c	2010-03-29 17:46:47.000000000 -0400
@@ -2393,15 +2393,16 @@
       /* Check for box coordinates. If present, update the frame size and 
        * reallocate the frame buffer.
        */
-      trajFile_fgets(buffer1,BUFFER_SIZE,trajInfo);
-      if (prnlev>0) fprintf(stdout,"DEBUG: Box Line: (%s)\n",buffer1);
-      numBoxCoords = sscanf(buffer1, "%f%f%f%f%f%f%f%f%f",
-			    &junk1, &junk2, &junk3, &junk4, &junk5, &junk6,
-			    &junk7, &junk8, &junk9);
-      if (totalAtoms > 2 && numBoxCoords < 9) {
-	isBox = 1;
-	trajInfo->frameSize += (numBoxCoords * 8 + 1);
-        trajInfo->buffer=(char*) realloc(trajInfo->buffer,(trajInfo->frameSize) * sizeof(char));
+      if (trajFile_fgets(buffer1,BUFFER_SIZE,trajInfo)!=NULL) {
+        if (prnlev>0) fprintf(stdout,"DEBUG: Box Line: (%s)\n",buffer1);
+        numBoxCoords = sscanf(buffer1, "%f%f%f%f%f%f%f%f%f",
+  			      &junk1, &junk2, &junk3, &junk4, &junk5, &junk6,
+			      &junk7, &junk8, &junk9);
+        if (totalAtoms > 2 && numBoxCoords < 9) {
+  	  isBox = 1;
+	  trajInfo->frameSize += (numBoxCoords * 8 + 1);
+          trajInfo->buffer=(char*) realloc(trajInfo->buffer,(trajInfo->frameSize) * sizeof(char));
+        }
       }
 
       /* Calculate number of frames. If not possible this could be a compressed