Index: src/export.c
==================================================================
--- src/export.c
+++ src/export.c
@@ -19,10 +19,17 @@
 */
 #include "config.h"
 #include "export.h"
 #include <assert.h>
 
+/*
+** State information common to all export types.
+*/
+static struct {
+  const char *zTrunkName;     /* Name of trunk branch */
+} gexport;
+
 #if INTERFACE
 /*
 ** struct mark_t
 **   holds information for translating between git commits
 **   and fossil commits.
@@ -161,10 +168,68 @@
   printf(" %s <%s>", zName, zEmail);
   free(zName);
   free(zEmail);
   db_reset(&q);
 }
+
+#define REFREPLACEMENT	'_'
+
+/*
+** Output a sanitized git named reference.
+** https://git-scm.com/docs/git-check-ref-format
+** This implementation assumes we are only printing
+** the branch or tag part of the reference.
+*/
+static void print_ref(const char *zRef){
+  char *zEncoded = mprintf("%s", zRef);
+  int i, w;
+  if (zEncoded[0]=='@' && zEncoded[1]=='\0'){
+    putchar(REFREPLACEMENT);
+    return;
+  }
+  for(i=0, w=0; zEncoded[i]; i++, w++){
+    if( i!=0 ){ /* Two letter tests */
+      if( (zEncoded[i-1]=='.' && zEncoded[i]=='.') ||
+          (zEncoded[i-1]=='@' && zEncoded[i]=='{') ){
+        zEncoded[w]=zEncoded[w-1]=REFREPLACEMENT;
+        continue;
+      }
+      if( zEncoded[i-1]=='/' && zEncoded[i]=='/' ){
+        w--; /* Normalise to a single / by rolling back w */
+        continue;
+      }
+    }
+    /* No control characters */
+    if( (unsigned)zEncoded[i]<0x20 || zEncoded[i]==0x7f ){
+      zEncoded[w]=REFREPLACEMENT;
+      continue;
+    }
+    switch( zEncoded[i] ){
+      case ' ':
+      case '^':
+      case ':':
+      case '?':
+      case '*':
+      case '[':
+      case '\\':
+        zEncoded[w]=REFREPLACEMENT;
+	break;
+    }
+  }
+  /* Cannot begin with a . or / */
+  if( zEncoded[0]=='.' || zEncoded[0] == '/' ) zEncoded[0]=REFREPLACEMENT;
+  if( i>0 ){
+    i--; w--;
+    /* Or end with a . or / */
+    if( zEncoded[i]=='.' || zEncoded[i] == '/' ) zEncoded[w]=REFREPLACEMENT;
+    /* Cannot end with .lock */
+    if ( i>4 && strcmp((zEncoded+i)-5, ".lock")==0 )
+      memset((zEncoded+w)-5, REFREPLACEMENT, 5);
+  }
+  printf("%s", zEncoded);
+  free(zEncoded);
+}
 
 #define BLOBMARK(rid)   ((rid) * 2)
 #define COMMITMARK(rid) ((rid) * 2 + 1)
 
 /*
@@ -413,10 +478,11 @@
 ** blobs written on exit for use with "--import-marks" on the next run.
 **
 ** Options:
 **   --export-marks FILE          export rids of exported data to FILE
 **   --import-marks FILE          read rids of data to ignore from FILE
+**   --rename-trunk NAME          use NAME as name of exported trunk branch
 **   --repository|-R REPOSITORY   export the given REPOSITORY
 **
 ** See also: import
 */
 void export_cmd(void){
@@ -431,10 +497,14 @@
   bag_init(&vers);
 
   find_option("git", 0, 0);   /* Ignore the --git option for now */
   markfile_in = find_option("import-marks", 0, 1);
   markfile_out = find_option("export-marks", 0, 1);
+
+  if( !(gexport.zTrunkName = find_option("rename-trunk", 0, 1)) ){
+    gexport.zTrunkName = "trunk";
+  }
 
   db_find_and_open_repository(0, 2);
   verify_all_options();
   if( g.argc!=2 && g.argc!=3 ){ usage("--git ?REPOSITORY?"); }
 
@@ -547,26 +617,22 @@
     const char *zSecondsSince1970 = db_column_text(&q, 0);
     int ckinId = db_column_int(&q, 1);
     const char *zComment = db_column_text(&q, 2);
     const char *zUser = db_column_text(&q, 3);
     const char *zBranch = db_column_text(&q, 4);
-    char *zBr;
     char *zMark;
 
     bag_insert(&vers, ckinId);
     db_bind_int(&q2, ":rid", ckinId);
     db_step(&q2);
     db_reset(&q2);
-    if( zBranch==0 ) zBranch = "trunk";
-    zBr = mprintf("%s", zBranch);
-    for(i=0; zBr[i]; i++){
-      if( !fossil_isalnum(zBr[i]) ) zBr[i] = '_';
-    }
+    if( zBranch==0 || fossil_strcmp(zBranch, "trunk")==0 ) zBranch = gexport.zTrunkName;
     zMark = mark_name_from_rid(ckinId, &unused_mark);
-    printf("commit refs/heads/%s\nmark %s\n", zBr, zMark);
+    printf("commit refs/heads/");
+    print_ref(zBranch);
+    printf("\nmark %s\n", zMark);
     free(zMark);
-    free(zBr);
     printf("committer");
     print_person(zUser);
     printf(" %s +0000\n", zSecondsSince1970);
     if( zComment==0 ) zComment = "null comment";
     printf("data %d\n%s\n", (int)strlen(zComment), zComment);
@@ -630,33 +696,34 @@
   manifest_cache_clear();
 
 
   /* Output tags */
   db_prepare(&q,
-     "SELECT tagname, rid, strftime('%%s',mtime)"
+     "SELECT tagname, rid, strftime('%%s',mtime),"
+     "       (SELECT coalesce(euser, user) FROM event WHERE objid=rid),"
+     "       value"
      "  FROM tagxref JOIN tag USING(tagid)"
      " WHERE tagtype=1 AND tagname GLOB 'sym-*'"
   );
   while( db_step(&q)==SQLITE_ROW ){
     const char *zTagname = db_column_text(&q, 0);
-    char *zEncoded = 0;
     int rid = db_column_int(&q, 1);
     char *zMark = mark_name_from_rid(rid, &unused_mark);
     const char *zSecSince1970 = db_column_text(&q, 2);
-    int i;
+    const char *zUser = db_column_text(&q, 3);
+    const char *zValue = db_column_text(&q, 4);
     if( rid==0 || !bag_find(&vers, rid) ) continue;
     zTagname += 4;
-    zEncoded = mprintf("%s", zTagname);
-    for(i=0; zEncoded[i]; i++){
-      if( !fossil_isalnum(zEncoded[i]) ) zEncoded[i] = '_';
-    }
-    printf("tag %s\n", zEncoded);
-    printf("from %s\n", zMark);
+    printf("tag ");
+    print_ref(zTagname);
+    printf("\nfrom %s\n", zMark);
     free(zMark);
-    printf("tagger <tagger> %s +0000\n", zSecSince1970);
-    printf("data 0\n");
-    fossil_free(zEncoded);
+    printf("tagger");
+    print_person(zUser);
+    printf(" %s +0000\n", zSecSince1970);
+    printf("data %d\n", zValue==NULL?0:strlen(zValue)+1);
+    if( zValue!=NULL ) printf("%s\n",zValue);
   }
   db_finalize(&q);
 
   if( markfile_out!=0 ){
     FILE *f;

Index: src/import.c
==================================================================
--- src/import.c
+++ src/import.c
@@ -216,13 +216,16 @@
 static void finish_tag(void){
   Blob record, cksum;
   if( gg.zDate && gg.zTag && gg.zFrom && gg.zUser ){
     blob_zero(&record);
     blob_appendf(&record, "D %s\n", gg.zDate);
-    blob_appendf(&record, "T +%F%F%F %s\n", gimport.zTagPre, gg.zTag,
+    blob_appendf(&record, "T +sym-%F%F%F %s", gimport.zTagPre, gg.zTag,
         gimport.zTagSuf, gg.zFrom);
-    blob_appendf(&record, "U %F\n", gg.zUser);
+    if( gg.zComment ){
+      blob_appendf(&record, " %F", gg.zComment);
+    }
+    blob_appendf(&record, "\nU %F\n", gg.zUser);
     md5sum_blob(&record, &cksum);
     blob_appendf(&record, "Z %b\n", &cksum);
     fast_insert_content(&record, 0, 0, 1);
     blob_reset(&cksum);
   }
@@ -513,10 +516,14 @@
   }
   zName[i] = 0;
 }
 
 
+static struct{
+  const char *zMasterName;    /* Name of master branch */
+} ggit;
+
 /*
 ** Read the git-fast-import format from pIn and insert the corresponding
 ** content into the database.
 */
 static void git_fast_import(FILE *pIn){
@@ -536,14 +543,15 @@
     if( strncmp(zLine, "blob", 4)==0 ){
       gg.xFinish();
       gg.xFinish = finish_blob;
     }else
     if( strncmp(zLine, "commit ", 7)==0 ){
+      const char *zRefName;
       gg.xFinish();
       gg.xFinish = finish_commit;
       trim_newline(&zLine[7]);
-      z = &zLine[7];
+      zRefName = &zLine[7];
 
       /* The argument to the "commit" line might match either of these
       ** patterns:
       **
       **   (A)  refs/heads/BRANCHNAME
@@ -559,15 +567,15 @@
       ** last commit that holds that tag.
       **
       ** None of the above is explained in the git-fast-export
       ** documentation.  We had to figure it out via trial and error.
       */
-      for(i=5; i<strlen(z) && z[i]!='/'; i++){}
-      gg.tagCommit = strncmp(&z[5], "tags", 4)==0;  /* True for pattern B */
-      if( z[i+1]!=0 ) z += i+1;
-      if( fossil_strcmp(z, "master")==0 ) z = "trunk";
-      gg.zBranch = fossil_strdup(z);
+      for(i=5; i<strlen(zRefName) && zRefName[i]!='/'; i++){}
+      gg.tagCommit = strncmp(&zRefName[5], "tags", 4)==0;  /* True for pattern B */
+      if( zRefName[i+1]!=0 ) zRefName += i+1;
+      if( fossil_strcmp(zRefName, "master")==0 ) zRefName = ggit.zMasterName;
+      gg.zBranch = fossil_strdup(zRefName);
       gg.fromLoaded = 0;
     }else
     if( strncmp(zLine, "tag ", 4)==0 ){
       gg.xFinish();
       gg.xFinish = finish_tag;
@@ -600,12 +608,16 @@
         gg.aData = fossil_malloc( gg.nData+1 );
         got = fread(gg.aData, 1, gg.nData, pIn);
         if( got!=gg.nData ){
           fossil_fatal("short read: got %d of %d bytes", got, gg.nData);
         }
-        gg.aData[got] = 0;
-        if( gg.zComment==0 && gg.xFinish==finish_commit ){
+        gg.aData[got] = '\0';
+        if( gg.zComment==0 &&
+            (gg.xFinish==finish_commit || gg.xFinish==finish_tag) ){
+	  /* Strip trailing newline, it's appended to the comment. */
+	  if( gg.aData[got-1] == '\n' )
+	    gg.aData[got-1] = '\0';
           gg.zComment = gg.aData;
           gg.aData = 0;
           gg.nData = 0;
         }
       }
@@ -618,21 +630,28 @@
       fossil_free(gg.zMark);
       gg.zMark = fossil_strdup(&zLine[5]);
     }else
     if( strncmp(zLine, "tagger ", 7)==0 || strncmp(zLine, "committer ",10)==0 ){
       sqlite3_int64 secSince1970;
-      for(i=0; zLine[i] && zLine[i]!='<'; i++){}
-      if( zLine[i]==0 ) goto malformed_line;
-      z = &zLine[i+1];
-      for(i=i+1; zLine[i] && zLine[i]!='>'; i++){}
-      if( zLine[i]==0 ) goto malformed_line;
-      zLine[i] = 0;
+      z = strchr(zLine, ' ');
+      while( fossil_isspace(*z) ) z++;
+      if( (zTo=strchr(z, '>'))==NULL ) goto malformed_line;
+      *(++zTo) = '\0';
+      /* Lookup user by contact info. */
       fossil_free(gg.zUser);
-      gg.zUser = fossil_strdup(z);
+      gg.zUser = db_text(0, "SELECT login FROM user WHERE info=%Q", z);
+      if( gg.zUser==NULL ){
+        /* If there is no user with this contact info,
+	 * then use the email address as the username. */
+        if ( (z=strchr(z, '<'))==NULL ) goto malformed_line;
+        z++;
+        *(zTo-1) = '\0';
+        gg.zUser = fossil_strdup(z);
+      }
       secSince1970 = 0;
-      for(i=i+2; fossil_isdigit(zLine[i]); i++){
-        secSince1970 = secSince1970*10 + zLine[i] - '0';
+      for(zTo++; fossil_isdigit(*zTo); zTo++){
+        secSince1970 = secSince1970*10 + *zTo - '0';
       }
       fossil_free(gg.zDate);
       gg.zDate = db_text(0, "SELECT datetime(%lld, 'unixepoch')", secSince1970);
       gg.zDate[10] = 'T';
     }else
@@ -1545,12 +1564,13 @@
 **
 ** The following formats are currently understood by this command
 **
 **   --git        Import from the git-fast-export file format (default)
 **                Options:
-**                  --import-marks FILE Restore marks table from FILE
-**                  --export-marks FILE Save marks table to FILE
+**                  --import-marks  FILE Restore marks table from FILE
+**                  --export-marks  FILE Save marks table to FILE
+**                  --rename-master NAME Renames the master branch to NAME
 **
 **   --svn        Import from the svnadmin-dump file format.  The default
 **                behaviour (unless overridden by --flat) is to treat 3
 **                folders in the SVN root as special, following the
 **                common layout of SVN repositories.  These are (by
@@ -1668,10 +1688,13 @@
     gsvn.revFlag = find_option("rev-tags", 0, 0)
                 || (incrFlag && !find_option("no-rev-tags", 0, 0));
   }else if( gitFlag ){
     markfile_in = find_option("import-marks", 0, 1);
     markfile_out = find_option("export-marks", 0, 1);
+    if( !(ggit.zMasterName = find_option("rename-master", 0, 1)) ){
+      ggit.zMasterName = "master";
+    }
   }
   verify_all_options();
 
   if( g.argc!=3 && g.argc!=4 ){
     usage("--git|--svn ?OPTIONS? NEW-REPOSITORY ?INPUT-FILE?");
@@ -1688,11 +1711,14 @@
   }
   db_open_repository(g.argv[2]);
   db_open_config(0, 0);
 
   db_begin_transaction();
-  if( !incrFlag ) db_initial_setup(0, 0, 0);
+  if( !incrFlag ){
+    db_initial_setup(0, 0, 0);
+    db_set("main-branch", gimport.zTrunkName, 0);
+  }
 
   if( svnFlag ){
     db_multi_exec(
        "CREATE TEMP TABLE xrevisions("
        " trev INTEGER, tbranch INT, trid INT, tparent INT DEFAULT 0,"