From d5682dd33775dc104029343f18ef5fb2a7135d39 Mon Sep 17 00:00:00 2001
From: Berk Hess <hess@kth.se>
Date: Tue, 25 Aug 2015 10:24:13 +0200
Subject: [PATCH] Simplify changing the tpx_version

Added an element tpxv_Count to the tpxv enum and setting
tpx_version to tpx_Count-1. When adding a new tpx version, one no
longer needs edit the tpx_version field, nor add a comma to the
next-to-last entry in tpxv. This results in fewer line changes and
reduces the number of git conflicts between two commits that both
add a new tpx version.

Change-Id: I23ea253678be369edbe721668a09b9062c641edd
---
 src/gromacs/fileio/tpxio.cpp | 50 ++++++++++++--------------------------------
 1 file changed, 13 insertions(+), 37 deletions(-)

diff --git a/src/gromacs/fileio/tpxio.cpp b/src/gromacs/fileio/tpxio.cpp
index 623c1d23fc..015ffad5f8 100644
--- a/src/gromacs/fileio/tpxio.cpp
+++ b/src/gromacs/fileio/tpxio.cpp
@@ -72,8 +72,7 @@
  * formats around which cannot be distinguished, while not causing
  * problems rebasing the feature branch onto upstream changes. When
  * merging with mainstream GROMACS, set this tag string back to
- * TPX_TAG_RELEASE, and instead add an element to tpxv and set
- * tpx_version to that.
+ * TPX_TAG_RELEASE, and instead add an element to tpxv.
  */
 static const char *tpx_tag = TPX_TAG_RELEASE;
 
@@ -82,10 +81,10 @@ static const char *tpx_tag = TPX_TAG_RELEASE;
  *
  * The enum helps the code be more self-documenting and ensure merges
  * do not silently resolve when two patches make the same bump. When
- * adding new functionality, add a new element to the end of this
- * enumeration, change the definition of tpx_version, and write code
- * below that does the right thing according to the value of
- * file_version. */
+ * adding new functionality, add a new element just above tpxv_Count
+ * in this enumeration, and write code below that does the right thing
+ * according to the value of file_version.
+ */
 enum tpxv {
     tpxv_ComputationalElectrophysiology = 96,                /**< support for ion/water position swaps (computational electrophysiology) */
     tpxv_Use64BitRandomSeed,                                 /**< change ld_seed from int to gmx_int64_t */
@@ -94,21 +93,22 @@ enum tpxv {
     tpxv_RemoveObsoleteParameters1,                          /**< remove optimize_fft, dihre_fc, nstcheckpoint */
     tpxv_PullCoordTypeGeom,                                  /**< add pull type and geometry per group and flat-bottom */
     tpxv_PullGeomDirRel,                                     /**< add pull geometry direction-relative */
-    tpxv_IntermolecularBondeds                               /**< permit inter-molecular bonded interactions in the topology */
+    tpxv_IntermolecularBondeds,                              /**< permit inter-molecular bonded interactions in the topology */
+    tpxv_Count                                               /**< the total number of tpxv versions */
 };
 
 /*! \brief Version number of the file format written to run input
  * files by this version of the code.
  *
- * The tpx_version number should be increased whenever the file format
- * in the main development branch changes, generally to the highest
- * value present in tpxv. Backward compatibility for reading old run
- * input files is maintained by checking this version number against
- * that of the file and then using the correct code path.
+ * The tpx_version increases whenever the file format in the main
+ * development branch changes, due to an extension of the tpxv enum above.
+ * Backward compatibility for reading old run input files is maintained
+ * by checking this version number against that of the file and then using
+ * the correct code path.
  *
  * When developing a feature branch that needs to change the run input
  * file format, change tpx_tag instead. */
-static const int tpx_version = tpxv_IntermolecularBondeds;
+static const int tpx_version = tpxv_Count - 1;
 
 
 /* This number should only be increased when you edit the TOPOLOGY section
@@ -141,33 +141,9 @@ typedef struct {
 
 /*
  * The entries should be ordered in:
- * 1. ascending file version number
- * 2. ascending function type number
- */
-/*static const t_ftupd ftupd[] = {
-   { 20, F_CUBICBONDS        },
-   { 20, F_CONNBONDS         },
-   { 20, F_HARMONIC          },
-   { 20, F_EQM,              },
-   { 22, F_DISRESVIOL        },
-   { 22, F_ORIRES            },
-   { 22, F_ORIRESDEV         },
-   { 26, F_FOURDIHS          },
-   { 26, F_PIDIHS            },
-   { 26, F_DIHRES            },
-   { 26, F_DIHRESVIOL        },
-   { 30, F_CROSS_BOND_BONDS  },
-   { 30, F_CROSS_BOND_ANGLES },
-   { 30, F_UREY_BRADLEY      },
-   { 30, F_POLARIZATION      },
-   { 54, F_DHDL_CON          },
-   };*/
-/*
- * The entries should be ordered in:
  * 1. ascending function type number
  * 2. ascending file version number
  */
-/* question; what is the purpose of the commented code above? */
 static const t_ftupd ftupd[] = {
     { 20, F_CUBICBONDS        },
     { 20, F_CONNBONDS         },
-- 
2.11.4.GIT